Daniel Kreiss and Shannon McGregor, reporting on another side of Facebook, Google, and Twitter during the elections:

For example, these firms offer an extensive array of campaign services — including advising campaigns on everything from the content of ads and other communications to the specific groups they might benefit most from targeting, and how best to reach them. Consider the fact that all three of these firms have dedicated partisan teams that work with campaigns. Staffers work with campaigns to guide advertising buys, boost engagement around online ads, and shepherd the use of their platforms.