The most likely candidate is the change in the News Feed algorithm that was announced months ago, that favoured “friends and family” (and later, local news). It took years to get that change approved, and that can only be because the team looking at it took a lot of time to prove that the positive impact of having that type of content was greater. Facebook announced exactly that type of consequence of the News Feed change in their financial statement, and that estimate was indubitably based on large-scale A/B testing.
Source for my intuition: I worked on something very close three years ago (at Facebook). Privacy scandals barely ever register at any company I worked; seemingly minor tweaks to the News Feed could have that compound impact.
Source for my intuition: I worked on something very close three years ago (at Facebook). Privacy scandals barely ever register at any company I worked; seemingly minor tweaks to the News Feed could have that compound impact.