In a way they already do, all political ads on facebook (in any country) are public information through their Ad Library Report: https://www.facebook.com/ads/li

In a way they already do, all political ads on facebook (in any country) are public information through their Ad Library Report: https://www.facebook.com/ads/library/report/?source=archive-landing-page&country=US https://www.facebook.com/ads/library/report/?source=archive-... Simply take their earning reports and divide one by the other and you'll get the percentage of revenue