You can't learn anything from a popup.
But you can learn a lot from the exclusive hacks sent in the Digital Marketing Superstars Community.
wpMails.com is a free weekly roundup of WordPress news and articles for keeping the readers in touch with what happens in WordPress Community. The first issue came out in late 2014 and since then the newsletter managed to gather more than 80,000+ subscribers from all over the world.
Squirrly SEO Featured in TOP 3 Best WordPress SEO Plugins, by Search Engine Watch Magazine
First thing first, here we have stats regarding which are the most read sections in the newsletter.