edinburgher - 8:42 am on Jan 30, 2013 (gmt 0)
I've always cared about the quality of my sites, so I block the spammy looking ads as soon as they appear. About a week ago I decided Adsense revenue had got bad that I'd experiment with clearing my entire block list. I removed every site and went through unblocking every single ad.
I expected more spammy ads to reduce CTR. However CPC should go up because there are now more advertisers bidding for the space (and some of those spammy ads take up a whole block). I hoped overall revenue would rise.
What I didn't expect was that CTR would stay roughly the same and CPC would *fall* still further. Did all the advertisers in different sectors reduce their spend at just the same time I decided on this experiment? Possible but unlikely.
I am, shall we say, a trifle peeved.