It's worth noting the difference between a fixed cost for sending a message, and a fixed inventory of messaging, and an auction bid system where bids are maximized by competition unless bidders form a cartel.

Funnily enough, if collusion is prohibited, the goal of such a law would be more competition, but the result is more mergers and monopolies, up until the point where antitrust kicks in and ad-hoc limits the monopoly, so each industry ends up with 1 bidder, or 2-3 tops