Why is there advertising on this blog?

After deliberating a while about letting Google's AdSense show ads on this blog, I decided to go for it. As an academic, I have no interests in monetizing these discussions. However, after some experiments with AdSense on this blog, I noticed that the ads I saw on my own screen actually were quite relevant to the topics (maybe Google knows too much about me already?). In my opinion, ads are "good" when they are relevant and timely (they are at least informative), and "bad" otherwise. Now, Google's definitions of good and bad should be aligned with my definitions, and hopefully this will produce both relevant and timely "advertising information". Remember, advertisers are there to sell products - and I am not. Most things I recommend here are indeed free (unless otherwise noted)!