I noticed that Google is getting pretty good at zeroing in on me with its targeted Gmail ads. As someone who always got a cheap laugh from creating Yahoo news alerts for "hell freezes over" and stuff like that (I loved when eBay had one of their "Low-priced ___, great selection!" ads on a page about... igloos), I started to wonder if any message at all would get an ad. I wrote myself an email with the subject "condolences" and a body "I am sorry to hear that your beloved cat miffy died." No ad--good job, Google! But then I thought maybe it was just too short for Google to get any analysis in, so I went back and forth with replies about losing a loved one, etc.--still no ads at all. Then I pasted in some text about Sony's audio CD malware, and poof! ads for blank CD-ROMs! Then I switched back to some "sympathy" type language, and then ads were for... blank CD-ROMs and websites with collections of sympathy poems.
It's good to know the bots have a little tact!