I think that the blogs that are copying the ad placing proposed by google for blogs receive low CTR then other blogs that make their own placing. I say this because the users migh click on a site that is having the scheme included but will not click again on other site that is using the same scheme. The problem is that too many sites are using the same placing. I want to know the opinion of other members about the problem of low CTR on blogs that use the optimization tips from google.
When it comes to blogs, getting relevant ads is very important. My blog posts that get the most relevant ads get the best CTR by far. Even over time my best CTR posts still get great CTR (especially the ones picked up by the search engines in the top 10). I do have blogs with less than 0.1% CTR though but they're aren't on topics that advertisers spend money on. Overall blending of the ads when it comes to blogs helps majorly. I recently changed one of my ad colors (to get rid of blending) and CTR dropped almost 3/4ths in just one day and stayed that way until I returned the colors back.