Not just are they not free, they are actually MORE expensive, since the $x has to cover the overhead of providing the at platform. There is also the hidden addi

Not just are they not free, they are actually MORE expensive, since the $x has to cover the overhead of providing the at platform. There is also the hidden additional expense of the marketing department and the expense to create the ad. If you were to pay, you would only have to pay the part that covers what the platform would earn on the ad. And then there is the design issue: if Facebook charged their users they would design Facebook so that it gave more value to you, instead of just sucking in as much time as possible.