tell me about it. I guess almost everyone who has an app on google play gets contantly spammed by these ad firms, install increasers, and review sellers.
that's what you get when google spits out everyone's email address on the store.
admob is for most people the way to go.
all the others... don't know... they all have articles about how it improved earnings for some developer(s) but it seems more like promotional sales talk.
If you try them you barely earn something compared to admob since they only do cpi.