true_INFP - 10:14 pm on May 8, 2010 (gmt 0)
ken_b, as you noted, the description you quoted is not a definition of "interaction with the advertisers". It is merely a general description of interest-based ads.
However, in the last few posts, we've been talking about the fraction of the ads that Google explicitly says you can't prevent from showing on your site. That is, ads based on interaction with the advertiser.
Based on the descriptions, any other interest-based ads (perhaps ~99% of them) can be prevented from being served on your site.