And, with publishers, you can get both monopoly _and_ monopsony problems. The latter is, I believe, one reason the attempt to consolidate from Big Five to Big Four failed -- I'm forgetting which two publishers were trying to merge, but angry authors talking about having difficulty selling books, and reduced pay for them, was a key argument.

CBS/Viacom was trying to unload Simon & Schuster. PenguinRandomHouse wanted to buy, but it ended up selling to a private equity company. A rare instance where that was actually the better option.