orcishgamer: They'd be pretty stupid not to, that's how I got all my expacs for Stardock games, by buying the jewel case only complete releases for like 10 USD and activating them. I would expect a lot of people who've bought Stardock games are used to this and doesn't Steam do this for other games?
Tizzysawr: Steam only does that for a handful of games, not for all, unless they're either Steamworks games (since those REQUIRE Steam) or Valve games. Non-valve, non-steamworks games that allow this are few.
I see, I guess I thought it was more common as so many indie bundles advertise the ability to activate on Steam (presumably because you want all that DRM goodness, that the bundle failed to deliver on, back).