Some great ideas in here about how to get people to engage and give up their email, without being so annoying about it.
1) Instead of pop-ups, create valuable gated content
2) Use NudgeSumo to replace pop-ups
3) Include subscribe forms directly in your content
Read how here:
I have 2 clients I'm going to speak with about this on Monday. If you'd like to be the third, Email Me or Get on my calendar