One of the most compelling arguments against real money transactions (rmt) in games is that allowing players to purchase in game progression for real cash destroys content. This is particularly true in reward motivated games where challenging content has to be overcome in order to get the reward. Allowing players to bypass that content and get the reward for a cash payment makes that content pointless for many players.
I came across a striking example of this last weekend when I bought Mad Balls Babo Invasion in a Steam weekend deal. Madballs is a somewhat anarchic yet nevertheless entertaining single player / multiplayer shooter. There is a mild rpg element in that beginners don't get access to all of the weapons and abilities but must unlock them over time by gaining experience in either single or multiplayer games. This is a fairly common feature of recent shooters like Modern Warfare and Team Fortress 2 but it does put new players at something of a disadvantage in multi-player versus games because they don't have access to everything yet. Playbrains have clearly thought of this because they offer an add on called the Anarchy Unlock pack that allows you to unlock everything in the game for only a couple of euros. In fact during the weekend sale you could buy a bundle containing the unlock pack for only about 60c more than the basic game.
That seems like a no-brainer, right? Many people thought so and bought the bundle. However they then discovered that the unlock pack not only unlocks everything in multiplayer it also permanently unlocks everything in single player and co-op games too. It was as if you got given all the goodies at the very start of the game and there was no way to give them back. Several disgruntled players posted to the Steam Forums saying that this spoiled the game for them. I suppose they could have played the game using an honour system, not using any weapon or skill until the point where it would legitimately be unlocked but of course the human brain doesn't work that way. By getting all of the goodies at level 1 these players felt they had lost the incentive to play the game. For these players RMT had destroyed content.
Fortunately this story has a happy ending. In an outstanding display of rapid response customer service Playbrains the developer of Madballs Babo have just released a mini patch which adds two new commands to the game: "Disable Anarchy" disable any unlocks you have not yet earned and "Enable Anarchy" which allows all the unlocks. This is less than a week after the complaints on the forums. Very impressive.