http://developer.valvesoftware.com/wiki/Steam_rating

Notwithstanding privacy settings, a user's page includes some brief personal information, links to any friends' user pages, details of any games owned, the number of hours of playtime during the past two weeks, a 0–10 Steam Rating of activity,[14] and links to any groups of which the user is a member. Users can also receive a feed of their friends' actions, including groups joined, games purchased, and Steam Achievements earned.