Check the link below for an overview of Kindle Profiles (via Guy Creese)
Kindle Profiles is a social service that was quietly launched by Amazon in March of this year. Its existence was little known, probably because it wasn't very useful as a social tool until Amazon recently added connections to Twitter and Facebook. I myself only discovered the service after VC Fred Wilson blogged about it the over the weekend. Kindle Profiles appears to be gaining some early traction now, thanks largely to Kindle Profile users auto-following people in their Twitter and Facebook networks. As Wired pointed out, this is a somewhat dodgy tactic - because the user cannot turn off this auto-follow behavior.