For years, the privately held company founded by Mark Zuckerberg in a Harvard dorm room put little effort into ad sales, focusing instead on making its service irresistible to users. It worked. Today more than 600 million people have Facebook accounts. The average user spends seven hours a month posting photos, chatting with friends, swapping news links and sending birthday greetings to classmates.
Now the Palo Alto company is looking to cash in on this mother lode of personal information by helping advertisers pinpoint exactly whom they want to reach.