As for there not being an RMT market for Guild Wars - for GW Prophies I just counted 25 different online shops on our site. That's a solid market.
However, I agree it is comparatively small compared to other games. My guess is that it's because of the lack of subscription fees. The demographic of the player base is different:
- It specifically attracted players who were not interested in monthly subscriptions (ongoing fees). The average purchasing power
is probably much lower than for games like WoW.
Another group are those that can't pay for subscriptions (minors, no credit cards, ... ). They will have a hard time purchasing currency (convincing parents, paying for currency if sellers only accept paypal...).
With lower income / age also comes the factor that their time is less valuable. A 35 year old farming gold for 8 hours (out of his weekly 12 hour "gaming time budget") might see it as a waste of time, for a 14 year old 8 hours of gameplay aren't that bad due to him having much more free time (30 hours?).
Last but not least - less emotional involvement. If you pay year after year for a game, your perception of how real and important it is, is probably much different than from playing a free game. You look at what you spent already and then have a much lower barrier to spend more.
Another good example of this is Runescape. It has 1 million paying (!) subscribers. Yet, the RMT market for it is pretty much non-existant. The demographic is mostly 14-18 years old, no credit cards (no PayPal accounts) with parents paying for the games. I imagine players would have a hard time explaining why parents should pay for virtual currency.
So to answer your question:
You can avoid RMT by targetting your game at people who don't have credit cards, paypal accounts, are minors, don't have a lot of income or are only casual players. However, that's not really a very attractive crowd for the majority of game companies and you need A LOT of players to make it worthwhile.
[Edited on 6/28/2007 by carebear]