Especially since Facebook's game from the beginning of the feed was clearly and openly user manipulation for profit, with the aim of expanding to encompass all of a user's monetizable activities on the web, whether inside or outside of facebook e.g. https://en.wikipedia.org/wiki/Facebook_Beacon

This is from the beginning. Wikipedia characterizes the Beacon episode with: "In general, Beacon was viewed as a mistake because it appeared to be too explicit about the intentions inscribed in its protocol."