I've seen several threads - unfortunately I don't have the links handy now otherwise it's would be useful for you. It's clearly something that those Adsense guys hate. I'm not so sure if it against TOS - but you'd likely to be penalized for it.
I have a question regarding traffic. What about buying traffic through the stumble upon? Isn't it against google TOS??
Not really, those are "real" visitors. Here is a piece from adsense TOS. all those who say that buying traffic is safe should read it. "Clicks on Google ads must result from genuine user interest. Any method that artificially generates clicks or impressions on your Google ads is strictly prohibited. These prohibited methods include but are not limited to repeated manual clicks or impressions, using robots, automated click and impression generating tools, third-party services that generate clicks or impressions such as paid-to-click, paid-to-surf, autosurf, and click-exchange programs, or any deceptive software. Please note that clicking on your own ads for any reason is prohibited. Failure to comply with this policy may lead to your account being disabled." source. buying traffic is a tricky business as traffic sources/validity is difficult to check. i would never send traffic from an unknown source to pages with google ads.
A lot of people have said it already that bought mass traffic is not safe. It'd simply trigger a warning to Adsense police about abnormal CPM. In fact, it is not because you bought traffic. It's just low quality traffic. People occasionally report that Digg traffic make their adsense accounts suspended. Even using Adwords is not safe, for they will flag you a potential arbitrageur. More investigation would be taken, and the chance your account got suspended is relatively higher.
This reasoning explains it all. Thanks mate. Hope everyone else notices this and escapes from being a trap of traffic sellers n decieve you saying the traffic is adsense safe. ANYWAY i even understood that the traffic doesn't convert(out of common sense).