How many of you who are running a Shopify Store put up all those banners and give them an X% discount just to have hope that they will buy someday? The chances are very low. You will end up paying money to your email service provider and they will go to JUNK and your unsubscribe rate will be higher. It's probably useless and less effective.
The problem is that they do not know your brand, and the chances of them buying anything from you because they filled a FORM is very low. UNLESS they are either referred by someone or have seen your ads (for ads I wrote a post before)
Now there goes the problem. What is the solution, Mr. Nik? The solution is to get email leads WHEN they BUY and when they are in the billing, because if they are in the billing then they are already READY to give their money to you, and are already giving you their information while they are doing that you can say "Hey! Do you mind giving us your email for the newsletter so that we can give you the discount? They will most likely say "Yep! You can have it".
Think of it this way.
You are John and you are going to a Mall in your city and you see an in front of the mall guy asking for your information for some offer, would you be comfortable doing that?
OR would you be comfortable giving the information to the same guy who asked you in the billing?
There are more chances that you will give the information to the guy at the billing counter because you already trust them.
Treat your e-commerce website as a Physical website, and you will have more success.
Now to answer your question of How I grew the Klaviyo Email list to 8K without Popups: I grew the Klaviyo Email list to 8K by asking them at the checkout and they said YES and since they are a customer they already trust the brand, and it has been so helpful that each email campaign generates at least 10X of the value.
And yes, I collected them using the checkout. 90% of them said YES, And that is how we have an open rate of 70% and a click rate of 5-14%.
The website still has some other email magnets in the footer menu and at some other places. But the whole point was to compare the difference between them.