Scurramunga - 10:22 am on Jan 25, 2006 (gmt 0)

From my experiences I have found that either changing and experienting with different ad formats/placements or shutting down underperforming ads helps me.

I have a very small website with only about 50 or so pages yet it is doing quite wll now since I rationed the supply of ads. I also hunt down the scummy advertisers (MFA's or poor content spammy sites) under the assumption that are very low payers, especially if they are expecting to pay for clicks and sitll make a profit as publishers within the same niche. Worst of all (I believe) that besides being unethical in many cases, that they insult your readers intelligence, destroy your site's credibility and repeat business.

There is a theory going around here which I subscribe to. That theory is that bad quality advertisers or off target ads lead to a poor conversion rate which in turn leads to the dreaded effects of smartpricing.

I don't know if you mentioned much about your ctr, but I am assuming that's down also. Look for unattractive unclickable ads such as ebay etc (if they are not relevant) because they only hog up valuable space sitting there contributing to a decline in your ctr.

In short get everything as targeted as possible. Also see my post re meta tags, that might be of some help.