IMHO use of steamworks, pricing policy and since they released Tomb Raider as a steamplay game I want to believe this might start a trend for the future.
Tomb Raider - $49.99 (available cheaper
anywhere else)
Tomb Raider Survival Edition - $57.99
Tomb Raider DLC - $39.74
Tomb Raider GOTY - $29.99
Or there's Deus Ex: Human Revolution: Director's Cut. $5 for people who already own everything in it, doesn't stack with sale discounts. Built off some alpha build of the game and has all kinds of problems
that are never going to be patched.
Or there's Final Fantasy XI (and, eventually, XIV). S-E releases their MMOs on Steam, but only long after their launch and they pull them down and put a new version up with every expansion. If you play through Steam, you need to delete your installation and reinstall it. There are better ways to handle this (look at how 2K/Firaxis handles Civ V, for example), this only works to the benefit of people who collect games, not to those who play them.
S-E is terrible. Both in regards to Steam and in general.
That reminds me -- apologies to Blizzard, who gifted me Mirror's Edge without knowing about my severe acrophobia; I slogged (and I do mean slogged) about halfway through the game, but it really took a lot out of me, as I couldn't play more than one chapter without having to lie down for a bit. Basically I don't think I can ever finish that game. If I had balls, they'd be shriveling into me every time I attempted a jump in that game.
I hear you can cure acrophobia pretty easily. Just watch Kim Novak fall to her death twice.