Your ecommerce signup form is the pickup line of your website, charming your customers into continuing a relationship with your brand.

A form might seem like a small part of your ecommerce marketing plan, but it’s a budget-friendly way to get people to opt in to get messages directly from your brand, which you can then use to build loyalty, inspire purchases, and more.

Making even minor changes to improve your signup form can help you grow your marketing list organically and rely less on expensive third-party acquisition channels like paid media.

Wondering what your best signup form might look like? Start with data from ecommerce stores across the world, including the US, the UK, mainland Europe, and more.

By the numbers: Key stats about ecommerce signup forms

Based on data from more than 80,000 online businesses using Klaviyo, here are some high-level stats to help you make data-driven decisions about your signup forms.

• Popup forms convert at a higher rate (3.2 percent) than flyout forms (2.2 percent)
• The top 10 percent of signup forms have submission rates of over 6 percent
• 85 percent of forms have two fields or less
• But, forms with up to five fields only see a small dip in conversion (<0.1 percent)
• Forms have higher submission rates on mobile (3.2 percent) than on desktop (2.3 percent)
• Forms asking for phone numbers and emails see similar submission rates (2.9 percent) compared to email-only forms (2.7 percent)

Wondering what to do with these numbers? Keep reading to learn how many fields your forms should have, whether you should include SMS in your signup forms, and more.

But first, let’s start with the basics: Signup form vocabulary.

Not all forms perform equally

There are three types of signup forms:

Embedded forms: These appear statically on a specific page on your site.

LivingProof includes an embedded form on their website footer:

Flyout forms: These slide into the browser’s window from any direction.

Tempo features a flyout form on their homepage:

Popup forms: These appear in the middle of the browser’s window.

Lust Home prominently displays their popup form on their homepage:

Each type of form has a unique customer experience, which results in different average conversion rates.

*Note: This high conversion rate is likely due to the fact that the most successful embedded forms tend to be on high-converting landing pages (e.g., high-stakes contests) rather than general-purpose or product pages.

Popup forms have the highest average conversion rate. Why?

Think about it this way: The more obvious the form, the more likely people are to notice it. And after noticing it—as long as the offer is relevant and appealing to the customer—they’re not shy in filling out their details.

Does that mean that every form you add to your online store should be a popup?

Probably not. When deciding what form type to use, consider three factors: your desire to grow your marketing list, your offer, and your customer’s experience.

While popups may be more intrusive to your customer’s experience, many brands prioritize list growth, which means they want to make their form as obvious as possible.

As long as you keep your offer relevant to your target customers, don’t shy away from using popups where you think they’ll be most impactful—but don’t forget to validate your hypothesis with a signup form A/B test.

The data behind mobile-first

Have you ever been online shopping on your phone, only to be interrupted by a popup that’s barely legible and clearly belongs on a full-sized computer screen?

That’s no fun. It’s a missed opportunity because the data shows that mobile users are more likely to submit a form than desktop users.

Here’s the average conversion rate for popup forms that appear on mobile versus desktop devices:

The takeaway: Test your forms on mobile and desktop individually—and even consider making two versions if your imagery or text doesn’t easily translate across device types.

More than half of all web traffic is mobile. If you look into your online store’s Google Analytics account, you can see exactly how many mobile users you have.

Mobile form images typically need to be horizontal to fit the screen without hiding the form fields. Similarly, make desktop forms easy to read on a monitor. Then, preview your forms after you make them.

With a device-optimized form, you can also add form elements that are unique to mobile phones.

For example, you can use click-to-text buttons that allow your subscribers to opt into SMS marketing in just two taps.

How many fields should your form have?

In the ecommerce world, brands typically keep their forms short and sweet. In fact, most forms only have one field.

With 85 percent of forms having two or fewer fields, it’s pretty clear that brands don’t want to risk asking for too much information, too soon.

But what does the data say about how likely someone is to fill out a longer form?

Short forms have the highest conversion rates, as expected.

But with each additional field, there’s only a gradual drop off in conversion rate. In fact, it’s not until there are four or more fields on a form that conversion takes a 0.1 percent hit.

Wilkinson Sword, a UK-based razor brand, learned this firsthand.

“We recently added a field to our signup form. Now, when people subscribe, they can click whether they’re interested in male or female products, or both,” says John Pagni, ecommerce assistant for the brand.

“Data about what people are interested in helps us provide them with relevant content, so we’re willing to sacrifice a bit of conversion for that. But we actually haven’t seen a drop off yet,” he went on to say.

Getting data straight from your customers is invaluable, and the data shows that people don’t balk at a form with some additional fields—just don’t go overboard, and make sure you test every change you make to understand how your unique audience feels about any additional fields on your forms.

Want to use zero- and first-party data to create better customer experiences?

Learn about Customer-First Data™

So, what extra questions might you consider testing on your form?

Look for which of your marketing messages already use personalizations successfully. Think automated Birthday emails, gender-oriented messages, first names in subject line.

Then, after you test including the field in your signup form, start using the data points to personalize and target your marketing messages as early as your welcome series.

If you really want to streamline your customers’ experience, create a multi-step form that lets them opt into email first. Then, in subsequent steps, ask them for additional information. That way, you’ll never sacrifice the opt-in.

How would adding SMS affect your form completion rates?

For many brands, SMS marketing is still an untested channel.

But consumers want to get SMS marketing as much as email. We know this because people are opting into text marketing at nearly the same rate as an email-only signup form.

The data shows that the two types of forms performed on par with each other.

Like additional form fields, asking for more information (in this case, a phone number) doesn’t necessarily mean you’ll see a drop in your form’s conversion rates.

If you can prove to someone that sharing their information is worth it, they likely won’t mind spending an extra two seconds filling out your form (yes, I timed it).

When done thoughtfully with best-practice forms, designs, and incentives, you might even find that adding SMS to your forms attracts some people who otherwise might have not subscribed to your email-only communications.

And, if you’re not sure whether your customers want texts from your brand, you can also create a multi-step form that offers SMS subscription after a customer has already signed up for email.

This data also shows the benefits of having all of your customer data in a single platform. Combining email, SMS, and forms in one provider eliminates delays between messages, duplicate messages, and duplicated attributions for revenue—all to help you seamlessly message your customers, no matter the channel.

With your email and SMS audiences united, you can even target only your email subscribers with an SMS-only form to attract your loyal customers to another key marketing channel.

Building your perfect signup form

Hopefully, this data has given you some ideas on how you can optimize your signup forms.

Keep in mind that these numbers are averages across countries, industries, and businesses—so the only way to know if your audience behaves similarly is by testing.

With your high-performing signup form, you can use the data you capture to create a personalized and irresistible experience your customers will love.

Ready to experiment with signup forms? Explore these five signup form A/B tests online brands swear by.

Want to combine signup forms, email, and SMS in one powerful marketing platform?