Companies producing advertising fail to understand that there is a certain surprise element in advertising. Place advertising in the right places and presto -- great results. Place those same ads in too many places then that surprise element is gone and people become weary of wading through ads.

In many ways, Google advertising on just about any site is almost going too far. If Google had kept their advertising to their own pages -- that surprise elements of just the right ad in just the right place when I was searching for something in particular would have been maintained.

Now putting the same ads in feeds -- you may as well forget advertising in with Googles Ad Services -- it is getting too common and click rates will drop.