ThatsBoBo - 3:05 pm on Jul 9, 2012 (gmt 0)
I never block an ad, and I believe blocking ads does nothing but cut your earnings.
If a belly-fat ad appears on your site and no one clicks it, Google's algo takes that into consideration next time it is in the auction. If no one is clicking the belly-fat ad, Google will stop displaying the ad, even if it has the highest bid.
By trying to guess which ads are bad for your site, and blocking them, you are reducing the number of ads competing for a spot on your site, thus driving down the winning bid and thus your earnings.
Google's algo knows a lot more about the user and ad performance than we do. In the long-run the best paying/clicked on ads will be displayed and you will make the most money.