Aren’t those keys for valve hosted games, meaning that they are taking full advantage of valve CDN… and so even though they’re being sold on a different site, they’re still being procured from valve? Way it reads to me, they’re not saying they can’t sell it cheaper on another market place, they’re simply saying if you’re using our infrastructure to distribute the game, don’t undercut what we are selling your game for.

Which doesn’t sound unreasonable to me… but I’m just a dude sitting in his office… so fuck if I know.