I put Google AdSense ads on an experimental (for my eyes only) blog as an experiment — what kind of ads would be served, I wondered. At first, I got public service ads, and then, only hours later, the ads started to be relevant. Between the first PSAs and the eventual ads, I input the URL (created only a couple of days ago) to Google’s Web search submission form. Was it the URL input and a (very fast) Web crawl that made the difference? Or were the ads acting as a homing beacon telling Google to crawl this page, pronto? Either way, I’m impressed.
UPDATE: it looks like the “homing beacon” idea was the proper one. I found “Mediapartners-Google/2.1” on my server log today.