>As Boland explains it, Facebook simply shows advertisers that a given number of people who saw an ad for a product also purchased that product.

Facebook doesn't share my personalized shopping data with advertisers. That's good.

But the data still exists. So the data the advertisers receive is only really anonymous until there's some sort of security breach or economic decision whereby it's suddenly more profitable to sell the personalized data. Either or Both of which are inevitable.

All in all, a moderately informative marketing piece.