MIT Technology Review, Tom Simonite, June 2012.
... And yet, even as Facebook has embedded itself into modern life, it hasn't actually done that much with what it knows about us. Now that the company has gone public, the pressure to develop new sources of profit (see "The Facebook Fallacy") is likely to force it to do more with its hoard of information. That stash of data looms like an oversize shadow over what today is a modest online advertising business, worrying privacy-conscious Web users (see "Few Privacy Regulations Inhibit Facebook") and rivals such as Google. Everyone has a feeling that this unprecedented resource will yield something big, but nobody knows quite what.
Heading Facebook's effort to figure out what can be learned from all our data is Cameron Marlow, a tall 35-year-old who until recently sat a few feet away from Zuckerberg. The group Marlow runs has escaped the public attention that dogs Facebook's founders and the more headline-grabbing features of its business. Known internally as the Data Science Team, it is a kind of Bell Labs for the social-networking age. The group has 12 researchers-but is expected to double in size this year. They apply math, programming skills, and social science to mine our data for insights that they hope will advance Facebook's business and social science at large. Whereas other analysts at the company focus on information related to specific online activities, Marlow's team can swim in practically the entire ocean of personal data that Facebook maintains. Of all the people at Facebook, perhaps even including the company's leaders, these researchers have the best chance of discovering what can really be learned when so much personal information is compiled in one place.
Facebook has all this information because it has found ingenious ways to collect data as people socialize. Users fill out profiles with their age, gender, and e-mail address; some people also give additional details, such as their relationship status and mobile-phone number. A redesign last fall introduced profile pages in the form of time lines that invite people to add historical information such as places they have lived and worked. Messages and photos shared on the site are often tagged with a precise location, and in the last two years Facebook has begun to track activity elsewhere on the Internet, using an addictive invention called the "Like" button.
... Marlow's team works with managers across Facebook to find patterns that they might make use of. For instance, they study how a new feature spreads among the social network's users. They have helped Facebook identify users you may know but haven't "friended," and recognize those you may want to designate mere "acquaintances" in order to make their updates less prominent
For one example of how Facebook can serve as a proxy for examining society at large, consider a recent study of the notion that any person on the globe is just six degrees of separation from any other. The best-known real-world study, in 1967, involved a few hundred people trying to send postcards to a particular Boston stockholder. Facebook's version, conducted in collaboration with researchers from the University of Milan, involved the entire social network as of May 2011, which amounted to more than 10 percent of the world's population. Analyzing the 69 billion friend connections among those 721 million people showed that the world is smaller than we thought: four intermediary friends are usually enough to introduce anyone to a random stranger.