incrediBILL, I was also exploring their SEO tools when I found about Adsense data. Blekko has in fact a lot of useful tools for webmasters and at first I was pleasantly surprised. But then you realize that what you learn about others... others can learn about you also, and there were no real benefits from being indexed by them as they're not sending any traffic. Still I wondered what others thought. I decided today to add them in the robots.txt of all my sites, especially after reading the no-archive thread [webmasterworld.com].