I guess its easy to see that a MMORPG is not quite like a usual game. To look a litle deeper on this we must look at two types of MMORPGs - Commercial and Free ones.
First up Commercial.
The commercial games work like this. Buy the game - get one month free usualy, then you are supposed to be hoocked on the game so that you will continue to play it. You pay a monthly fee to play it. Most people will probably pay this by credit card, and credit cards continue to pay the membership for you. very sketchy for stolen cards and such. In addition to this they may charge you a fee to do stuff like respecing and stuff
So whats the pros and cons of this? - No Ads, and the company will have money to pay for servers, mainetence and updates
Cons - It costs money to play it! , unlike a regular game you can pay for once.
Free games are free to install, and also free to play but still they gotta make some money from somewhere. Some have some sort of membership, members basicly pay so others can play for free. The second option is a system based solely on micro transactions. and i think this system is the most interesting and also the one open for more discussion.
Okay so what does it mean to have P2P contra F2P and if you pay to get advantages.
me myself i find P2P quite okay, but its a thin line if P2P or F2P is going to be too powerfull. Mikro-transactions on the other hand... you pay for something, it could be items or some kida ability. It creates an inviroment where if you have money you can get unfair advantages. Not cool. Real World Trading with real money for the loss.