Michele was talking about making AdSense work on web forums and how hard it is to get regulars to click on ads because they are so used to the site they are just about blind to AdSense. Michele talks about a method used by some of interfering with the river of information in a thread by juxtapositioning ads between posts in a thread.
To me that is just being rude and just a way to trip up and ignorantly disrupt viewing a thread. It would inspire me to just write a greasemonkey script to block the ads.
What I think may work instead is something like an AdSense Ad mixed in with Google Suggest, which brings you to a site search page.
So, on a forum where someone talks about their XP font size issue, they see an Ad from Google stating “Search Google for XP Font Size issues” which brings you to a nice results page with a few Ads. You get a cut of those ads. An example below for a DVD search:
Importantly enough I think they have to say they are Google links since Google is almost a guarantee of quality. As well as ads they are quite a handy tool for those looking for information. So why not make money from those people who can’t find what they’re looking for from your site?
In fact search results too for VBulletin forums and the like should have this as the default. Results from VBulletin lined up with results from Google or an option to “Try Google for the same search.” To me this would be far less intrusive and would be a genuine way of helping users of your site.