roycerus - 5:57 pm on Jul 14, 2005 (gmt 0)

Well I personally do not believe that ECPM and the number of impressions have NO effect on your earnings. Something called smart pricing does exist and we do not clearly know what it's algorithm does.

What I have seen however is showing one ad on a page more profitable. The reason is very simple to understand. Google will show the most high performing ads on your first block. If there is a second block it kind reduces the probability of getting that click on the first block. However, with the addition of the CPM ads, I think things have become a bit more complicated. I think if you have CPM ads on your website, it's best to have two ad blocks and maybe an Adlink [if it performs well for you]

Regards,
R