I was responding to a pdf viewing (using java) question on Artima - http://www.artima.com/forums/flat.jsp?forum=1&thread=96447&start=0&msRange=30.

After I submitted my comments I noticed that the first AdSense ad contained the same link I had posted!
Looks like very soon AdSense may supplement the java and other technology experts!
The funny thing was the previous response which states - no way you can do it! Surely he blackholed the AdSense ad like many of us do :)

Seriously though it is not surprising at all. In fact this is the basic premise of AdSense, to provide context sensitive ads which will induce people to actually look at them in the hope of finding something useful. With sufficient advertisers that may soon be a reality. Next time around when faced with a question which nobody answered I would surely cast a glance that way.