DaStarBuG - 10:38 pm on Oct 18, 2010 (gmt 0)
If click rates go down you can try to deactivate "Interest-based ads".
I run a medical forum with high click prices.
After deactivating Interest-based ads my earnings increased.
If a user is on my site he should see medical ads fitting the content he is watching and not some ADs for shoes because he viewed a website on shoes a few times before.
I remember once (before I opted out of interest based ads with a cookie) I was searching for a toy for my niece and after that I was bombarded with toy ads for several weeks. If I would click on ads regularly many publishers would have missed out on a possible click because the toy was bought and I had no more interest in toys.
Just a thought that might be interesting for some of you ;)