Time for a concluding post on the f2p debate.
First, I'd like to thank the most active commenters, Tesh, Max, Gilded, Kring, and Psychochild (in no particular order, hehe). Also, Psychochild made a post of his own on the topic.
I know that arguing often feels like repeatedly running against a wall. So I'd like to point out that these discussions actually did change my mind. I'm not suddenly in favor, of f2p business models, but I did learn a few things.
One thing I learned was that a game based on monthly subs can and often does use the same psychological tricks that I outlined in the last post. I was aware of the fact that they used tricks, too, but not really aware of the magnitude. The point I am making has therefore shifted. I now think that microtransactions are often worse than subscriptions, because the effect of using the psychological tricks has a potentially worse outcome for the player.
The worst thing that can happen to you in a monthly sub game is that you pay a monthly sub although you didn't want to or didn't actually play. Taking todays subscription fees, that's a maximum expense of about $15 per month. In a f2p game with microtransactions and itemshops, however, you can often spend without limit.
Moreover, the psychological tricks when you use them on a monthly sub game, mostly make the players play more than they actually wanted. For example, a sunken-cost fallacy in combination with a daily dungeon may encourage me to play a game daily, instead of only on weekends. This is in contrast to a f2p game where the tricks encourage you to spend more than you actually wanted. (Actually, it is questionable whether a monthly sub game does even has an interest in me playing daily and as exessive as possible).
In retrospect, I prefer to find out that I played exessively during the last two weeks to finding out that I spent money exessively during the last two weeks. The reason is that the time would now be gone anyway and the odds that I had done something particularly productive in my free time are small. However, the money is something I would still own if I hadn't spent it.
Paying $15 every month is also different from spending 0.67 cents every few hours. Most people do some calculations when confronted with the monthly payment options. But they are less likely to do this when facing micro transactions. Which is, of course, exactly the point. I just want the companies to encourage the consumer to make an informed, transparent and well-thought-out choice in contrast to encouraging impulse buying.
My advise, if you really want to use microtransactions and itemshops to finance your game, is to make them as transparent as possible. This is not easy, because the management and the marketing department will feel like not doing their job, when they don't use the psychological tricks outlined in the last post. But manipulating players to spend money that they didn't actually want to spend is not an honest way of allowing them to reward your efforts! These tricks are powerful! They work especially well on children and less educated people, who usually don't have much money to begin with.
I know that there are other cultures, especially in parts of Asia and right-wing U.S., but the culture I grew up in despises efforts to make poor people spend beyond their means.
Concluding, I'd like to point out again that my main argument against item shops in virtual worlds is that they destroy my immersion: the feeling that I play in one coherent, credible and consistent virtual world. Moreover, I fear the corruptive influence microtransactions have on a game company - especially when it comes to immersion, which often seems to be a frail flower to begin with.