It’s been clear for a while now that the greatest value of social media to marketers won’t come from placing ads on social sites — it’ll come from using social data to improve the ads marketers place everywhere else. We call this idea the database of affinity, and we believe it could be the Holy Grail for more-effective brand marketing. For nearly a year, Google has helped marketers use the database of affinity to improve the targeting of their online display ads. And today Facebook has finally started to build the database of affinity that has always been its birthright, launching a mobile ad network.

This move is fantastic, if long overdue, news for marketers. It has the potential to improve the performance of all mobile advertising. And if Facebook grows its ad targeting business into other channels and works to better analyze and utilize its data (something it’s lagged at in the past), it could revolutionize brand advertising.

For more analysis on what this means to the mobile ad ecosystem, read my colleague Jenny Wise' take here.