jff: Well they only stated that there were invalid clicks, then pointed to their policy on what they define what an invalid click is, which can be plenty of things. Although they haven't given any details about why. And yes I'm saying the truth about the clicks, why should I lie? 

I still have to see what service can suite my blog.

Manowar: Well I don't mean popups, it's just a div docked in the document. I don't feel it's true intrusive. Although that scenario about that you were describing could happen. Well I don't have to pay for hosting too (I provide hosting for myself), although even if I had to pay it would be dead cheap.

The idea of having ads, in my opinion, is just trying to make some profit of what you're display in the web (capitalism at it's best).