@DanielIser

The "we are using cookies" thing is not a pop up, it's a required notification.

A "subscribe to my newsletter" thing IS a popup. With plugins like optinmonster, I haven't even finished reading the FIRST paragraph of an article and it pop ups.

Most people including most commenters here find those intrusive and annoying.

Look at how many popup blockers there are around. People find INTRUSIVE popups

If you want people to subscribe to your newsletter, put a form on the sidebar.

If you want people to get the pro version of your plugin/theme then put a regular banner on the header or sidebar

and so forth, no need to use popups