How Facebook Knows What You Really Like

http://www.wired.com/wiredenterprise/2012/05/facebook-open-graph/

Using Open Graph, Spotify — the digital music service — lets you share your listening habits with your network of Facebook friends. Netflix lets you share what movies you’re watching. Little snippets of your online behavior are streamed into the Facebook Newsfeed and onto your Facebook Timeline, and ultimately, this feeds the habits of your online friends.

As those 900 million people use Facebook, clicking on objects here and there, Vernal and company record this behavior in a software platform called Scribe, a technology specifically designed to log large amount of data in realtime. Then a second (unnamed) platform taps into Scribe and does a kind of on-the-fly analysis of this data, determining what’s the most popular and what’s the least. These tallies are then stored in a third system based on Hbase, the open source distributed database.

The tallies stored in Hbase are then shuttled to Facebook’s Newsfeed and Timeline platforms, and there — in tandem with a similar analysis of your personal behavior — they’re used to determine what Open Graph data you see and what you don’t.