I do hate now how all the pop-ups get worse and worse but look at it this way. The more annoying the pop-ups are, the less likely someone will return to the site but almost more likely you will get one click out of a couple people because they accidently hit it. Other than that, you get nothing. I think if people would use Google Adsense which are related to the topic then I think they would probably make even more money than they think they are getting with their pop ups