Let's list possible reasons for getting banned from G (and other s.engines) or adsense. There is a webmaster guidelines and adsense rules. Other than these what are possible reasons for getting banned, smartpriced,..? Link exchange ok, but link scheme not ok? What is the difference. If you join a blog network and get too much traffic, is this ok or not? What if you get traffic from popups? What if you get traffic from form-send? I prefer never getting close to borders of acceptability, but it is good to know where exactly they are.