It is hard to believe that Stumbleupon can actually get AdSense account ban for invalid impression fraud!
Apparently, many bloggers that practised Stumbleupon experienced such a case with Google AdSense when they received an email telling them their account is banned. Why? It appears that, Google detects massive traffic source from stumbling would not have visitors clicking on the ads thus generates very low CTR, results in unintentionally making impression fraud.
Did anyone of you receive such email before? Perhaps it was caused by Stumbleupon that caused your accounts to get invalid ad impressions, since Google never tells you why you were banned anyway. I guess having too high CTR or too low CTR will be a problem to you.
I am new to the Stumbleupon function, thus I went to find a review of it before I tried stumbling. That’s when I came across a few articles reviewing about it with some horror Google stories behind. Creepy!