Billing models discussion thread

I decided to open this thread to talk about the billing models which you like to see in your MMO games. Right now, is common for developers and publishers to profit from their games through one of three approaches:

- Subscription based: Or pay to play. It's the most traditional method for MMOs, and still remains the most profitable among the western playerbase, although it's been gradually losing support on these last years. Apart from producing gigantic profit margins for the game companies, this model is considered to attract better-than-average communities. It does so in the sense that people unwilling to take a game seriously tend to also be unwilling to pay for it; on the other hand, the players on these games often feel psychologically pushed to rush through the content as fast as possible, which often reduces the quality of their experience.

- Purchase the box: Or buy to play. Classic model for non-MMO games: you buy the game's box (and potentially those of its expansion packs) and you can play the game freely without having to pay anything extra at any point. This is (combined with some F2P strategies) the road choosen by the recently released Guild Wars 2. It takes care of the need to rush through the game, but the communities are not as filtered as with subscription games.

- Free to play: Very popular, and currently adopted by almost all low or medium budget titles (as well as some AAA ones who feel can't keep their players any more through subscriptions). Playing these game is free, no initial purchaches and no monthly payments. They generate revenue through optional microtransactions: additional features, costumizations or benefits which can be acquired in exchange for real money. As trendy as it is, this choice still has its issues: mainly the unfiltered community, and a microtransaction selection which may put off players. Although it wasn't too much of a problem among the oriental market (where this model started gaining track), the latter tends to bring on an strong rejection by occidental gamers, with issues like holding off crucial game content from non-paying players or pay2win (*) transactions.

Aside from those three, other less common billing models exist. It's the case of the games enabling real money transactions between players and taking a cut from them (see Real Money Auction House in Diablo 3), or those which add in-game advertisement from real brands (recently announced as one of the revenue means to be implemented in the next Blizzard MMO, Titan). Of course, any combination of the known models is possible, too.

So, getting back to the original question: what would be your model of choice? any combination or original occurrence that you would like to see implemented?

(*) A note on pay2win: A game is considered pay2win when it allows microtransactions which provide a player with an unfair advantage over the others, and is considered a no-go by most western gamers. Since it's a designation made up by the community the limits of its reach are not clearly cut: whilst a game where you can buy equipment superior to that obtainable in-game is almost univesally considered pay2win, and purely cosmetic features are generally not, there's divergence about things like XP bonuses or game features also available through in-game means (like League of Legends). Every person has a limit on what he or she considers acceptable, and that's what counts; pay2win is just a word, and diiscussing its meaning is not the purpose of this thread.