Comment spam prevention for blogs.
http://akismet.com
Widgets · Comment System
Get access to data on 1,297,521 websites that are Akismet Customers. We know of 182,396 live websites using Akismet and an additional 1,115,125 sites that used Akismet historically and 106,652 websites in the United States.
Get a list of 1,297,521 websites using Akismet which includes location information, hosting data, contact details, 182,396 currently live websites and an additional 93,040 domains that redirect to sites in this list. 1,115,125 sites that used this technology previously and 106,652 websites in the United States currently using Akismet.