How to Build an Email List in 2025
What is email list building, and why does it still matter in 2025? If you’ve been wondering how to get emails that actually convert — not just inflate your numbers — this guide will walk you through the most effective methods for building a mailing list that drives long-term value.
Email marketing isn’t shiny or new, but it continues to be one of the highest-ROI channels – an average return around $36–$42 for every $1 spent. The reason? Unlike social media, you own your email list. There’s no fickle algorithm throttling your reach or sudden platform policy change wiping out your audience. If a customer subscribes, you have a direct line to their inbox – your message gets delivered without having to “pay-to-play” or pray the algorithm shows it. That’s why starting an email list early and investing in email collection tools is crucial for sustainable growth.
Equally important, building your email list is a first-party data strategy that’s important in the privacy-first environment. With third-party cookies on the way out, brands are doubling down on permission-based datalike emails. Marketers now offer real value (exclusive content, insider incentives) in exchange for emails, because relying on rented audiences (like social followers) is risky. And an opt-in email list gives you consent-based access to customers.
Foundational email list building strategies (that still get overlooked)
Before diving into shiny new tactics, let’s answer the core question: how do you build an email list from scratch that actually performs? These best practices for email list building are foundational — they help you set up a mailing list that doesn’t just collect contacts, but generates ROI.
Opt-in clarity
Be crystal clear about what subscribers are signing up for and why it’s valuable. Your sign-up form should plainly state the benefit of joining like “Get weekly style tips and 10% off your first order”, not just say “Subscribe to our newsletter” with no context. Clarity builds trust. When people know exactly what they’ll receive, they’re far more confident opting in to join your email list. Whether you're collecting just a name and email or additional data, keep the promise of value front and center. A clear value proposition paired with a simple email format can dramatically increase conversion.
User intent & context
Consider where and how you ask for an email. The best marketers collect email addresses where intent is highest. Align your offer with the user's current experience — for example, if someone is reading a blog post, a subtle slide-in with a related guide or announcement about new email content feels like a natural extension. This kind of context-aware opt-in isn't just a best practice — it’s a powerful tool in your email marketing strategy.
If a shopper is browsing products, a pop-up offering a discount can be the nudge they need. This is a great opportunity to sign up for your email list using a value-driven offer. Don’t forget to think through the places to promote your email — from blog posts and product pages to checkout flows. And if they’re about to leave? An exit-intent popup is your last chance to use email to stay in touch. The better you tailor the moment, the better your email marketing campaigns will perform later through smarter email segmentation.
Mobile-first form design
If your sign-up forms aren’t mobile-friendly, you’re literally turning away potential subscribers. Today, basic email forms just won’t cut it. Prioritize responsive, mobile-optimized design for every email capture form. That means easy-to-tap buttons, legible text, and forms that don’t get cut off or overwhelm the small screen. Consider using mobile-specific triggers (like a popup that only shows on exit-intent for mobile, or a simplified banner). In fact, studies show modal pop-ups actually see higher opt-in rates on mobile (around 7.9% on mobile vs 4.4% on desktop on average). At a bare minimum, test your forms on a phone.
When it comes to email templates, ensure they’re just as mobile-friendly so your whole email marketing strategy stays seamless from signup to inbox.
Quality over quantity
It’s easy to fixate on growing a huge list, but a smaller list of engaged, interested customers beats a large list of idle addresses every time. Focus on attracting subscribers who truly want to hear from you – people who opt in because they value your brand, your email newsletter, or your content. These are the subscribers who are most likely to open, click, and convert — and they help you grow your list in a sustainable way.
To build your email list with long-term success in mind, you may need to narrow your targeting and personalize your offers. Requiring a double opt-in (confirmation email) helps filter for truly interested users. This means every person who chooses to join your email list is more likely to engage, improving your open rates and preserving your sender reputation.
Remember, your goal isn’t just to collect addresses — it’s to promote your email list in a way that brings in high-quality new email subscribers. Avoid tricks or giveaways that bring in disengaged users. Instead, focus on delivering real value through great content and incentives so that your email list organically attracts the right audience.
If you're ready to learn how to build a list that performs, this is your foundation. It’s the smarter path to effective, permission-based communication — and a hallmark of the best email marketing strategies today.
The heart of creating an email list for business: Form-first approach
Too often, marketers treat the email opt-in form as a minor afterthought – a little widget tucked in the footer or a generic popup slapped on the site. But your forms aren’t just filler — they’re the foundation of your effective email strategy. Every list is a collection of potential buyers and loyal fans — and every form is a gateway to grow it. When you treat your forms seriously, you’re not just trying to build email capacity — you’re creating meaningful entry points that build a relationship from the very first click. Whether you place a form on your homepage, product pages, or checkout, it should be optimized with care. The right email sign-in message and incentive can instantly turn curious visitors into subscribers.
Adopting a “form-first” approach means you plan your email capture strategy as deliberately as any ad campaign or checkout flow. Rather than slapping one generic newsletter box on your site, you design forms (plural!) for different pages and audiences, optimize their copy and design, and test them rigorously. Treat each form like a mini landing page for your newsletter – with compelling headlines, visuals, and a clear call-to-action. Each one is a stepping stone in building your list faster and smarter.
Also, ensure your forms are easy to find. Don’t hide the signup in a hard-to-notice corner. Use banners, popups, and slide-ins to encourage visitors to subscribe to your list without disrupting their journey. When you give your email capture forms the attention they deserve, you’ll see far better results in email list growth. And never forget: a good email list isn’t built with tricks — it’s built with trust. That’s why you should never buy an email list. Instead, attract the right people and turn them into email subscribers through real value.
Email list builder tools like Claspo make this easy — they give you the flexibility you need to build high-performing forms that convert. From design to targeting, you can test what works and keep iterating. It’s one of the smartest ways to build a clean, engaged email list that drives results. When your forms are optimized with context, mobile design, and A/B testing, they become your secret weapon for creating email lists for marketing campaigns.
Sign-up forms as micro-conversions: rethink your funnel
Marketers often obsess over the big conversion (the sale). But successful email marketing starts earlier — with the mini-win of a signup. That’s why every time someone completes an email sign-up form, it’s a conversion worth celebrating. It shows they’re ready to subscribe to your email, and that first step is everything. It helps to rethink your funnel: instead of only “visitor -> customer,” consider “visitor -> subscriber -> customer”. Each time someone fills out an email signup form, it’s a micro-conversion – a pivotal little win that moves a prospect closer to an eventual purchase.
Capturing that email is often the second-best outcome if they don’t buy on the spot. Think of it this way: you work hard to drive traffic to your store – through ads, SEO, social media, etc. If 100 people visit your site and only five make a purchase, the other 95 don’t have to be lost. Capturing even a few of their subscribers’ email addresses gives you a second chance. Maybe 3-5 out of 100 visitors weren’t ready to purchase, but were interested enough to give you their email for a discount or content offer. That's why smart marketers use forms to collect a high-quality email before users leave.
Those are 3-5 people you didn’t lose forever – you now have a chance to nurture them via email and eventually convert them to customers. Track how many people see a form vs. submit it (the form’s conversion rate) and optimize that just like you’d optimize add-to-cart or checkout rates. For instance, if an exit-intent pop-up appears 1,000 times and 30 people sign up, that’s a 3% conversion – is that good? (It’s about average; many pop-ups convert ~3-5%, with top performers hitting 10%+).
This process — converting casual traffic into a collection of email addresses — is how you build a relationship that pays off later. With a form-first mindset, you continuously refine those micro-conversions: maybe A/B test different form copy, optimize your email signup CTA, or try a more enticing incentive to lift that rate. Each gain in signup conversion directly increases your contact list growth, which in turn creates more future sales opportunities. Don’t forget to integrate these micro-conversions into your analytics funnel. For example, tag new subscribers and watch their behavior: how many end up purchasing later? By valuing the email signup as an official step in the customer journey, you’ll be more motivated to optimize it. So, start looking at sign-ups as goal completions just like sales – because they truly are mini-conversions that feed your larger sales funnel.
So many marketers overlook this: the best way to build an email list from scratch is to treat email signups as a conversion in their own right. You’re not just collecting data — you’re learning how to generate an email list from real human behavior. By tracking micro-conversions, you’re building a smarter funnel for long-term growth. Every signup is more than a name in your ESP or other email marketing platform. It’s a sign of interest — and with the right nurturing, you can keep your email strategy strong and active.
“At Simpro, our email list growth was stalling, and the typical pop-up strategies just weren’t working. Our audience is mostly tradespeople and field service pros, so generic incentives like “Get our newsletter” fell flat. The turning point came when we aligned the opt-in flow with their pain points. Instead of broad CTAs, we offered time-saving tools—like downloadable job quote templates or automated checklists—in exchange for email signups. Relevance drove action, not just design tweaks.
We also used AI to segment by industry, like plumbers, electricians, HVAC techs, and dynamically served opt-in forms with industry-specific content. That personalization boosted form completions by 38% without annoying users. No flashy spin-to-wins, just clear value.
Unsubscribes dropped once we tested our incentive follow-ups. Rather than hammering users with promos, we created onboarding email drips based on their first download, educational, not sales-heavy. AI helped us spot drop-off points and tweak tone and timing.
Gamification wasn’t flashy but practical; we introduced “toolkits” where each piece unlocked after engagement, subtly nudging users to stay subscribed. The real win was that users didn’t feel sold to, they felt supported.”
Sara Cooper
Director of Web Strategy, Simpro
Form use case mapping
Not all signup forms should be treated the same. Want to make a mailing list that converts? Then you need to meet your users where they are in their journey. Map your forms to specific user scenarios: first-visit welcome overlays, contextual product page offers, exit-intent savers, cart capture, and post-purchase invites. Each has a role in engaging users at different points in their journey. By covering these bases, you create a net that catches visitors wherever they are in the funnel, giving you multiple opportunities to convert traffic into subscribers.
Creating mailing lists through homepage popups, cart recovery forms, and post-purchase CTAs is a strategy, not a one-size-fits-all move. Let’s break down key places to deploy email capture forms on a typical e-commerce store, and why each location matters:
- Homepage overlays: your homepage is often where first-time visitors land, so it’s the best place to use a email form created with the help of an opt-in template. Use targeting to ensure this popup appears at an appropriate time – for example, after the visitor has had a few seconds to absorb the page or on their second pageview, rather than immediately in their face. A homepage popup works to capture interest early, turning curious browsers into subscribers before they wander off. Just be sure to use frequency capping so it’s not shown on every visit, which can annoy repeat visitors.
- Product page forms: on product pages, the visitor’s intent is a bit more focused – they’re considering a specific item. Here you might employ a different tactic. Instead of a generic newsletter signup, consider a slide-in that’s contextually relevant. The idea is to leverage the product interest: if they don’t buy today, you at least get a way to follow up. Product page forms are subtle and often work best as inline blocks or slide-ins, so they don’t completely interrupt the shopping experience.
- Exit-intent popups: these are the classic “Wait, before you go…” popups that trigger when a visitor’s mouse moves toward the close/tab bar (on desktop) or when scrolling behaviour suggests they’re about to leave. Since the user was ready to leave, you have nothing to lose – and a well-thought exit offer can salvage a portion of those abandoners. These forms treat an impending exit as a trigger to convert “almost lost” visitors into leads. Just be sure your offer is juicy enough to grab attention at the last moment.
- Cart recovery forms: when a customer adds items to cart but hesitates or starts to leave, an email form can act as a safety net. One approach is an exit-intent popup specifically on the cart or checkout page: “Get an extra $X off your order if you sign up and complete your purchase today!” This serves both as an opt-in and an incentive to finish checking out. Another approach is a small form or checkbox in the cart like “Email me my cart” or “Save my cart for later” which collects their address (with permission) so you can follow up if they abandon the cart. Cart recovery forms help capture high-intent shoppers who just need a nudge or a reminder. Since these users are very close to buying, even a modest signup incentive (or simply the promise of a cart reminder email) can be effective. Integrating with your email platform, you can then send an abandoned cart email sequence to try and convert the sale. It’s all about turning cart abandonment into an email conversation rather than a lost sale.
- Post-purchase upsell forms: after a customer completes an order, you might think you have their email (you do, from the order) – but due to privacy rules, that doesn’t always mean they’ve consented to marketing emails. Many Shopify stores include a checkbox at checkout for “Subscribe to our newsletter” which is one way to get opt-in at purchase. Beyond that, consider a form or call-to-action on the order confirmation page encouraging them to officially join your list or loyalty program. Since a buyer is obviously interested in your brand, convincing them to stay engaged for future offers is easier at this moment. The key is to upsell the relationship – turn one-time purchasers into repeat customers by keeping them in the loop through your email content. Just ensure you differentiate transactional emails (which they’ll get anyway) from marketing ones, and obtain proper consent.
Best practices for designing sign-up forms that convert
A signup form is more than a box asking for an email — subtle design and copy choices can dramatically impact whether people actually subscribe. A well-created form is your first step toward unlocking the potential of email marketing. Here are some best practices for designing high-converting forms.
Keep it short and simple
Every extra field or step you add will generally drop your conversion rate. The golden rule is to ask for as little information as you need. Often, just an email address (and maybe first name, if you plan to personalize emails) is enough at the sign-up stage.
Data have shown that even asking for a seemingly innocuous extra piece of info – like a first name – can hurt conversion if it’s not truly necessary. One case saw a 120% increase in form submissions by cutting the number of fields from 11 to 4. The easier and faster it is to subscribe, the more people will do it. (Bonus: You’ll also get fewer fake “John Doe” names – another benefit of fewer fields).
Create personalized CTA
The call-to-action button text is a small but mighty element. Avoid the bland default “Submit” or “Subscribe” if possible – instead, use the CTA to reinforce the value or speak in the subscriber’s voice. For example, a button that says “Yes, send me insider deals!” or “Get my 10% off code” is far more enticing and clear. Data show personalized or benefit-focused CTA copy significantly improves engagement – one case found that personalized call-to-action links had a 42% view-to-submit rate, outperforming generic CTAs. The best CTA text often includes an action and a benefit (e.g. “Get My Discount” or “Join & Get Updates”). It performs better and shows that subscribing to your email list has real benefits.
Use eye-catching but relevant visuals
Humans are visual creatures – a form with an image or some graphical element can often outperform a plain one. In fact, one case found that adding a relevant image to an email popup increased conversions by about 63% (from a 2.6% to a 4.3% submission rate). Images can draw attention to your form and help communicate your message. Ensure the visual complements the offer and doesn’t distract from the form fields. Also, be mindful of file size so it doesn’t slow down loading — especially when using email marketing software that loads dynamic pop-ups on mobile.
Consider multi-step forms for more info
If you do need to collect a bit more data, consider breaking it into multiple steps rather than one intimidating form. Multi-step signup forms (for example, Step 1: email, Step 2: name and preferences) can sometimes convert higher because the first step is so easy (just email) that users get started, and then they’re more likely to complete the second step. Each step should have a clear purpose – first get their consent to join, then ask optional profile questions. The first step should always be the simplest (email only) to secure the opt-in; any further details are bonus. Plus, multi-step forms make it easier to introduce email automation right from the beginning — allowing you to personalize follow-ups through automated email sequences triggered by step-two inputs.
Balance friction with incentive
There’s often a trade-off in form design: the more you ask of the user (friction), the more you should offer in return (incentive). For example, if your form has several fields (perhaps you truly need them for a good reason), make sure the perceived value of signing up outweighs that hassle. This could mean sweetening the deal (a bigger discount, a free gift for subscribing, etc.). On the flip side, if your incentive is modest, keep the sign-up dead simple. Always put yourself in the user’s shoes – would you fill this form as is for the offer being presented? If not, either reduce the friction or boost the incentive.
Design for clarity and UX
Lastly, some general design tips: ensure the form is easy to read (clear fonts, adequate font size, and contrast). Labels and placeholder text should be unambiguous (“Email address” means email – don’t get cutesy and say “Your info” which could confuse). Arrange the form layout logically, and on mobile make sure inputs are vertically stacked with enough spacing for fingers. Always include a visible close button on pop-ups – trapping users is a surefire way to irritate them. If using an inline form, leave enough padding around it so it’s noticeable but not disruptive in the content. Great UX helps keep your email list clean and active — because when users have a smooth experience, they’re more likely to trust your brand and stay subscribed.
And pay attention to triggers – a pop-up that appears at the wrong moment (like immediately on page load, or while someone is in the middle of reading) can hurt both conversion and user experience. A/B test timing if possible: some cases have found that a slight delay or trigger (scroll percentage, etc.) can improve conversion versus instant pop-ups.
Value offers that make people want to subscribe
Even a beautifully designed form won’t capture emails if you don’t give people a compelling reason to subscribe. Most consumers guard their inbox carefully – you have to earn that email address with a promise of value that speaks to them. If you’re still wondering how to build an email list for free, this section is for you. Offers like free shipping, gated content, or giveaways are the cornerstones of how to start an email list without paid ads. Each of these is a form of email capture — and when paired with the best email capture tools, they become powerful assets in building an email list in digital marketing. Here are some proven incentive ideas (and a few fresh twists) that actually make people want to sign up.
First-order discounts
A classic for a reason. Offering a percentage or dollar discount on the first purchase in exchange for subscribing is perhaps the most popular e-commerce incentive. “Get 10% off your first order when you join our list” is straightforward and effective – who doesn’t like instant savings? Just make sure the offer is significant enough to matter (5% might not move the needle, whereas 10-15% or a $10 off coupon has more pull). It can also be framed as a coupon code revealed upon sign-up or emailed to them (which has the nice side effect of driving them to check their email). Pro tip: If everyone in your niche does 10%, consider upping it or adding a small free gift to stand out. And ensure the discount is applied easily (provide a unique code or auto-apply it when they use the sign-up email at checkout).
Free shipping or upgrades
Free shipping can be as enticing as a discount, especially if your products have a shipping cost that customers begrudge. A sign-up offer like “Join our email list for free shipping on your first order” can overcome a common purchase barrier. Similarly, other small “upgrades” work – for example, subscribe and get a free sample added to your first order. These incentives reduce friction in the purchase process and feel like a bonus value. They work well if your pricing model has room to absorb those costs. As always, make the terms clear (e.g. “free standard shipping on your first order, no minimum”).
Gated content
Content can be a powerful magnet. If you produce valuable content that’s relevant to your audience, offer it in exchange for an email. This could be a downloadable ebook, a PDF guide, a cheatsheet, a recipe booklet, a styling guide, you name it. The key is the content should be useful and aligned with your products, effectively attracting potential customers interested in what you sell. These are often called lead magnets, and they can pull in subscribers who might not be ready to buy yet but are hungry for knowledge or inspiration. Make sure whatever you offer is high quality – it represents your brand, after all. A bonus benefit: subscribers who consume your content often become more educated and engaged customers down the line.
Exclusive or early access
People love feeling like insiders. Use your email list as a club that gets early access to new products, limited edition “drops”, or private sales. For instance, “Subscribe to get first access to our new summer collection (before it’s public)” creates excitement. If your brand does product launches or flash sales, this is a great angle. Knowing they will be “the first to know” or have the chance to buy limited stock items before everyone else can strongly motivate fans to sign up. This marketing strategy works particularly well for brands with hype around their products or any sort of limited availability. It’s less about a financial incentive and more about exclusivity and belonging – which can be just as compelling for the right audience.
Giveaways and contests
A time-tested list builder is running a giveaway contest where entering requires an email sign-up. For example, “Sign up for our newsletter for a chance to win a $200 gift card” or a bundle of your products. Contests can generate a lot of sign-ups quickly, especially if promoted on social media. The upside is volume; the downside is you may attract freebie-seekers who aren’t deeply interested in your brand. To improve quality, make sure the prize is highly relevant to your target customers (e.g., your own products or something only a niche enthusiast would love). That way you attract people who genuinely care about what you offer. Also, don’t overdo contests – an occasional giveaway can spike interest, but it shouldn’t be the only reason people stick around.
SMS + email bundled offers
As SMS marketing grows, many brands try to capture phone numbers alongside emails by sweetening the pot if you subscribe to both. For instance, your form might say: “Get 10% off (or 15% off if you opt into text updates too).” By bundling an SMS opt-in with the email opt-in, you provide extra incentive for the customer to share a phone number as well. This can be a win-win: you grow two valuable channels at once. Just be sure to clearly state what they’re signing up for in each case (and comply with SMS consent regulations – usually a checkbox or separate consent for texts). The subscriber perceives it as getting a bigger reward (e.g. an extra 5% off) for a bit more info.
Community or VIP club perks
Sometimes the incentive is less tangible: it’s about belonging or getting content others don’t. For example, framing your list as a “VIP Club” or community where members get exclusive newsletters, how-to tips, or behind-the-scenes updates can attract those who are true fans. “Join our community of insiders for weekly styling tips and member-only surprises” – this speaks to those who want more than just promos; they want connection or knowledge. If you can deliver engaging content (like a newsletter that isn’t just salesy, but actually interesting), this alone becomes a reason to subscribe.
Whichever value offer you choose, make sure it’s prominent and crystal-clear on your form. People should immediately see the benefit: “Oh, if I sign up, I get that.” Also, deliver on that promise right away. If it’s a discount, the next page or email should give the code with no hassle. A pro tip from seasoned email marketers: stack your value. That means, if possible, give email subscribers multiple reasons to be happy they joined.
Measuring and optimizing email subscriber list building efforts
You can’t improve what you don’t measure. As you implement your list-building tactics, be sure to track performance so you can optimize over time. Marketers know the importance of data, so apply that mindset to your email sign-up efforts as well.
Don’t just track how many people opt in. Real success comes when you create a mailing list and then monitor how it behaves. Want to know how to get an email list that turns into revenue? Measure your growth rate, source quality, and post-signup conversions. Here are the key metrics and methods to focus on.
Form view-to-submit rate
For each signup form or popup, track how many people see it vs. how many actually submit their email. This conversion rate is the primary success metric for your forms. For example, if an overlay was displayed 1,000 times and 50 people signed up, that’s a 5% conversion – not bad. Different types of forms have different typical rates (a well-timed popup might do 3-5%, an in-page embedded form might be lower unless it’s very compelling). Use these numbers as baseline and try to improve them. You might find one form placement vastly outperforms another – great, double down on what works. Or maybe your product page signup is lagging at 0.5%; that’s a flag to try a new approach there. On top of that, Claspo provides this stat for you in the Analytics section.
Industry benchmarks suggest that good popups convert around 2-5% (with top performers higher), but your goal is to continually beat your own past performance. Treat it like a game: can we tweak the homepage offer to raise its rate from 3% to 4%? Even small lifts mean a lot more emails over time.
New subscriber engagement
Don’t just measure the act of subscribing – measure how those new subscribers behave afterwards. Key metrics here are the open and click-through rates of your welcome messages or first few email campaigns to new subscribers. If 80% of new subscribers open the welcome email, fantastic – they’re clearly interested (and that probably means your incentive was aligned with their expectations). But if only 20% open your emails after joining, that could indicate a disconnect or low-quality signups. It might mean your signup incentive attracted people who don’t actually engage (for instance, they wanted the discount code and then ghosted). Or it could mean your subject lines/content aren’t delivering the expected value.
By looking at engagement of new vs. older subscribers, you can gauge lead quality and adjust tactics. For example, if subscribers from your “free ebook” offer have higher opens than those from the “contest giveaway” offer, that tells you something about incentive quality. Over time, you want to optimize for sources and signup methods that yield engaged subscribers, not just raw numbers.
To keep your list in top shape, maintaining a clean and accurate database is essential. Once you’ve started collecting email addresses, you’ll want to ensure your list is free of invalid or outdated addresses. Using tools to verify bulk emails instantly ensures that your messages reach valid, active subscribers, helping to minimize bounce rates and improve overall deliverability. Regularly cleaning your email list will improve your sender reputation and boost your email deliverability, ultimately enhancing the performance of your email marketing efforts.
List growth rate
This is more of a business-level metric, but track how fast your list is growing month over month. Factor in unsubscribes too. If you added 500 emails this month but 100 unsubscribed, net growth is 400. A healthy engaged list should be growing as your business grows. If growth plateaus or declines, dig into why – do you need to drive more traffic, improve form conversion, or are you losing people due to content issues? Sometimes a flat line in list growth could be due to an overly aggressive pruning of inactive subscribers, which might be fine, but you generally want a positive trend. You can set goals like “Grow your email list by 20% this quarter” and then derive tactics (campaigns, new forms, partnerships, etc.) to hit that.
Source attribution & segmentation
If possible, tag or segment subscribers by where they signed up or via which form. For example, segment A came from the homepage popup, segment B came from a specific landing page, segment C from a social contest. Then compare their engagement or conversion to customers over time. This is a more advanced analysis, but it can provide powerful insight. You might discover that subscribers from the cart recovery form have a 15% higher customer conversion rate than those who joined via the generic homepage form – likely because they were closer to purchase when they signed up. These insights help you prioritize high-value list-building activities. If one segment underperforms (e.g. contest signups rarely turn into buyers), you might dial back that tactic or handle those subscribers differently (maybe they need extra nurturing).
A/B testing & experimentation
To make an email list perform better, you need to experiment. Testing form layout, triggers, and messaging is one of the most underrated ways of how to grow email lists at scale. A/B test your forms and offers regularly to keep improving results. This means trying two versions of a form to see which one yields more signups. You can test all sorts of elements: the headline (e.g. “Join our newsletter” vs “Get 10% off – Join us”), the incentive itself (10% off vs $5 off, or vs free shipping), the form design (light vs dark theme, image vs no image), the timing (show after 5 seconds vs 15 seconds), etc. It’s important to test one variable at a time for clean results. As an example of how impactful this can be: one company found that simply changing their CTA button color to a brighter one increased conversions by 32% in an A/B test.
Another test might reveal that a more urgent headline outperforms a generic one. Don’t “set and forget” your forms – continuously experiment. Even if you’re getting a solid 5% conversion, a new tweak could bump it to 6% or 7%, which is a big win over thousands of visitors. A/B testing is a best practice many still ignore, but not you – you’ll use data to squeeze the most out of your email marketing efforts.
Ultimately, the end goal of building an email list (for an e-commerce marketer) is to drive sales. So one of your longer-term metrics to watch is what percentage of your subscribers eventually become paying customers. You might measure, for example, the 60-day conversion rate: of all subscribers who joined in the last two months, how many made a purchase? This helps quantify the ROI of your list-building.
If you find that, say, 10% of subscribers purchase within 60 days and their average order is $50, you can estimate how much revenue each new subscriber is “worth” to you (in this case, ~$5). Then you can justify ad spend or effort to acquire subscribers at a cost lower than that. It also lets you compare list-building to other acquisition methods. Maybe email signups convert better and cheaper than straight cold ads – information that could lead you to allocate budget towards getting more email leads. Keep in mind this metric will vary widely depending on your industry and sales cycle, but it’s arguably the north star of your list quality.
Parting words
If you’re asking how to create an emailing list that performs — start here: value-driven sign up forms, tested incentives, and behavior-based placement. Whether you're using the best email list builder on the market or just getting started, these are your email marketing tools to create an email subscription list that works for business, not just your ego.
In 2025, setting up an email list isn’t a checkbox — it’s a competitive edge. So if you’ve been wondering how to create an email list and how to set up a mailing list that people actually care about… this is your roadmap. And if you’re ready to start building an email list from scratch or want to start a mailing list with tools that don’t hold you back, Claspo makes it easy. Our free forever plan gives you full access to every feature — from advanced targeting and A/B testing to mobile-optimized templates and gamified popups.
