My preliminary experience with site match would have to be described as a failure. Quite a bit of money spent for many thousands of impressions. Zero conversions, which is even lower than my past experience with the content network. Even using the minimun 2.00 cpm advertising model, my effective cost per click is way way higher than either the search or content networks.
Some people may be willing to pay for brand awareness that may result from impressions without clicks. But, I will be surprised if people have success with this from an ROI standpoint.
One suggestion that I have is that Google up the sophistication of this to allow the user to select ad-blocks that are either "above the fold", "left column" "right column", "inline" or "bottom of the page". When paying by impression , this is critical information. Many of the suggested sites to the topics I tried were fine web sites that were relevent to my ad, but the ads were placed at the bottom of page so that it wouldn't even be seen, unless the user scrolled down. I don't think it is reasonable to assume that the user scrolled down to see the ad, yet I am guessing that we are being charged for an impression. Even worse on one site, the ads only appeared if you scrolled horizontally to the right on an 800x600 screen. I am guessing very few people scroll right to see that ad.
Regards
