They hire ad / "lead" companies to collect emails of people who have clicked on an ad, or entered their email saying they support A, B, or C and give them permission to post a comment on their behalf. So in theory each comment has someone who gave the company permission to post a comment for them. BUT if you tell an ad company "hey here is $2 million, get us X number of emails" they're going to produce X emails even if there are not X amount of people. The actual fake profiles come from "publisher" websites that generate fake clicks or leads. Usually the ad or lead companies will have some sort of system to detect fake / spam responses... but $2 million is a decent incentive to maybe loosen their standards a bit.