PCMag: New research from Facebook and the Università degli Studi di Milano reveals that most of the social network's users are just 4.74 steps away from each other. If you take any two random Facebook users, you'll be able to connect them in five degrees 99.6 percent of the time, and you'll be able to connect them within four degrees 92 percent of the time. When you look at two people in the same country, they can usually be connected within three degrees.
The study also revealed that Facebook now has 721 million active users, more than one-tenth of the global population. The average user has 190 "friends."