To be fair for Watchmen, the Watchmen deal was made at a time where paperback reprints were rare, and they obviously kept reprinting it because they genuinely wanted to make money from directly selling it, not because they were reprinting 10 copies a year just to keep the contract from expiring.
I don't think that's verifiable without receipts. I'm pretty sure at some point (late '90s) you could get such paperbacks on the secondhand market for pennies, and everyone had one already.
