There are about 2.5 million executable files in Google’s index:
“Results 1 – 10 of about 2,470,000 for filetype:exe” – http://www.google.com/search?q=filetype%3Aexe.
That’s pretty interesting, considering how these can be used for trojan viruses and other dirty work. Of course, not all .exe files are dirty, but this is pretty significant. In addition, there’ve recently been posts in the SEO community about how this type of file won’t rank / will be less trusted.
Kudos to Pete Wailes’ post for the filetype query inspiration:
BTW, Pete’s comments are some of the most value added at SEOmoz, and his contributions are pretty sweet too. Kudos to this excellent online marketing services provider for sharing his knowledge!
If I had time, I’d dig around the top 100 results for that file extension query, see what they’re trying to rank for and whether there’s any patterns. That would be a fascinating research piece.