signor_john - 7:28 pm on Dec 12, 2008 (gmt 0)

While AdSense has been dropping, my other ad networks have been rising to make up the difference.

Same here. AdSense is mostly pay-per-click, while my display ads are sold on a CPM basis, and targeted display ads from large corporations are more about brand-building than about immediate gratification in an economy where consumers may be delaying purchases.

Addendum: This thread [webmasterworld.com] cites an article that may be worth reading if you're concerned about falling eCPM.