I've used popups on and off in the past for email optins, still haven't cracked the code for getting high conversions but one thing I learned is that all the popup makers are ridiculously expensive ($19+ a month per site). Tried OptinMonster in the past but always refunded due to the high cost relative to the value I was getting. Optinly seems to have all the same features but offers way better value (I got unlimited deal) so it should pay for itself in a few years. Five tacos.