My pet theory on the pricing of DD PC games. Won't be useful to most folks so probably worth skipping:Spoiler
Very interesting. I understand the industry not wanting Steam going unchallenged but as long as they are doing this pricing stuff with Steam keys then the players still remain in the Steam ecosystem which is the biggest boon to Valve.
Any time that I make a digital purchase on PSN or XBLA or various other non-Steam/non-Desura services I am quickly reminded how much of a time-saver it is to have the most current version of a game download all patched and ready to go as an 'image' rather than the absolute clusterfuck of something like PSN. (download 3GB game only to have it need to be installed and then patched with a conveniently sized 3GB patch)
That's why I seek out Steam and Desura keys because I'm lazy and spoiled and not in the mood to hunt down patches or re-download entire games due to an update. (which can still happen on Steam and Desura depending on how the game is structured)
I'm not loyal; I'm lazy.