Facebook, longtime friend of data brokers, becomes their stiffest competition

Facebook was for years a best friend to the data brokers who make hundreds of millions of dollars a year gathering and selling Americans' personal information. Now, the world's largest social network is souring that relationship — a sign that the company believes it has overshadowed their data-gathering machine. 

Facebook said March 28 that it would stop data brokers from helping advertisers target people with ads, severing one of the key methods marketers used to link users' Facebook data about their friends and lifestyle with their offline data about their families, finances and health. The data brokers have for years served a silent but critical role in directing users' attention to Facebook's ads. They also, critics say, stealthily contributed to the seemingly all-knowing creepiness of users seeing ads for things they never mentioned on their Facebook pages. A marketer who wanted to target new mothers, for instance, could use the data brokers' information to send Facebook ads to all women who bought baby formula with a store rewards card.