What Is Email Opt-in? Single vs Double Opt-in

Quick Definition

Email opt-in is a shopper's permission for you to send them marketing emails. They give it by typing their address into a signup form or ticking a box at checkout. It's also called an email signup. With single opt-in, the signup counts right away. Double opt-in makes them confirm through an email link first.

Single Opt-in vs Double Opt-in

There are two ways a signup can join your list:

Single opt-in: the shopper types an email and presses subscribe. They're on the list right away.
Double opt-in: the shopper gets a confirmation email first. They join only after they click the link inside it.

Single opt-in is faster, and fewer people drop out. Double opt-in adds a step. In return, it filters out typos and fake addresses, and it shows the person really asked to hear from you.

Example: A coffee roaster's footer form gets 300 signups in a month. It uses double opt-in, and 210 people click the confirm link. That's 7 in 10, so the list ends up 90 names shorter. Some of those 90 typed things like "gmial.com." Others never opened the email. But all 210 addresses work, and each person chose to be there.

Why Permission to Email Matters for Sales

Most visitors leave without buying. Getting them back often means paying for another ad click. An opt-in gives you a direct line instead, for a restock, a sale or a new product.

There's a legal side too. Many countries require consent before you send marketing email, and the rules vary. A clear opt-in shows the shopper said yes.

Where Shoppers Opt In on Shopify

Theme forms: many themes include a newsletter box, often in the footer.
Checkout: Shopify's checkout can show a checkbox for email news and offers.
Pop-ups: email apps often add a signup pop-up, sometimes with a discount code as a thank-you.

Shopify saves each customer's answer as their email marketing status, such as subscribed or not subscribed. You can filter your customer list by it. There's also a double opt-in setting if you want new subscribers to confirm first.

Want a discount pop-up without adding an app? You can build one with our free Shopify discount popup builder.

A Bigger List Doesn't Mean More Sales

Many stores treat list size as the goal. A "10% off for your email" offer can bring in lots of signups. But some of those people would have paid full price, so the code only cut your margin. Others use the code once and unsubscribe. It helps to tell dedicated buyers from walk-away customers before you decide who gets a reward for signing up.

A better test is what subscribers do later. Do they open and click your emails? Do they come back to buy? Watch out for pre-ticked boxes, too. A box ticked before the shopper touches it isn't a real opt-in. Under the EU's GDPR, it doesn't count as consent.