Social networks are redefining the way people find and share information, they've provided a platform for a new wave of applications, and their impact has even spilled over into this year's revolutions in the Middle East. The operators of these networks make money primarily through ads, wooing advertisers with the prospect of campaigns better targeted than anything competitors like search engines or television can provide. But can online communities manage their privacy problem?
- By Stephen Cass
A single page on a social-networking website is an amalgam of many different technologies. Each user is served a unique page assembled from up-to-the-second information from multiple sources. During assembly, attention must be paid to each user's personal preferences, the privacy settings of the user's friends (and friends of friends), and the advertisements that seem most likely to find a favorable reception (see "Managing Users by the Million"). Here we show some of the hardware and software required to support key elements of a typical page belonging to one of Facebook's 600 million active users.