Google introduces site targeting for contextual ads

"Cost-per-click bidding for placement targeting

With the launch of cost-per-click (CPC) bidding, advertisers can now choose the bidding option that best matches their needs. If the purpose of your placement-targeted campaign is to increase sales, leads, sign-ups, or other conversion-oriented metrics, you can select CPC bidding and pay when users click on your ads. If you want to maximize impressions and increase brand awareness among your target audience, you can select cost-per-impression (CPM) bidding. And you can specify either the maximum price or the average price (with preferred bidding), that you'd like to pay for each click or 1000 impressions."
http://adwords.blogspot.com/2007/11/two-updates-to-site-targeting.html

 

I like the idea of CPM bidding, considering I use image only adsense ads

 

have you been able to compare the cpm of image-only ads to the cpm of text ads on your site? because cpm ads usually pay lower than cpc ads, but it could depend on the content... forums might be better for cpm ads.

are you getting 100% fill rate with the image ads?

 

just got this email from adsense support:
"Thanks for your inquiry. Currently, we don't offer CPC site targeted ads separately from CPM ads. If you opt into site targeting, you'll receive both CPC and CPM ads. If we offer separate CPC site targeting in the future, we'll be sure to let you know."

which means that you'll have to take the bad with the good(?) here.

 

I give 100% fill rate with image only ads and very decent pay, but i also have 1,000,000+ adsense ad pageviews a day