graeme_p - 4:54 pm on Sep 16, 2011 (gmt 0)
I wonder if people are becoming ad blind about the SERPS and scrolling past? I do it automatically.
Also, three ads is a maximum. Most of my searches show no ads.
I do not believe Google will ever charge for inclusion. They know it would destroy the value of the SERPS: there is too much good content by people who do not make money from it, and who will never pay.