How Facebook rewards polarizing political ads

by Casey Newton

I wrote about the incentives baked into Facebook advertising system, and how they're changing the content of political ads.

As the debate intensifies around Russian ad buys in the US election, a fundamental aspect of Facebook’s platform has gone mostly overlooked. Facebook’s auction-based system rewards ads that draw engagement from users by making them cheaper, serving them to more users for less money. But the mechanics that apply to commercial ads apply to political ones as well. Facebook has created a powerful system that dynamically, and unpredictably, changes the prices of political ads. The system also encourages polarization by incentivizing ads that users are predisposed to agree with.