europeforvisitors - 9:11 pm on Jul 6, 2006 (gmt 0)

When we did participate in the content option...the clicks from adsense produced zero conversions to sales.

Several travel advertisers have told me personally that they've had very good results with AdSense, and some of the "Ads by Gooooogle" advertisers on my own pages have been using AdSense almost since the beginning. So maybe success depends on the topic, the keywords, and judicious use of the domain-blocking feature.

I do think that lack of advertiser control over audience is the biggest weaknesses of current PPC networks, and it's almost certainly limiting the networks' popularity among advertisers and media buyers who are used to having that control. Google currently offers "site-targeted CPM" ads on a run-of-site basis. If and when it (or a major competitor) offers site-targeted contextual CPC ads, new opportunities will open up for the ad network, advertisers, and publishers.