There will always be someone better, and as long as there is still new tricks to learn and new moves to master, players will continue to play and compete. PvP will keep players interested and loyal when newer prettier games hit the market. Not only does it reduce the amount of new stuff that a company will have to produce, but it also reduces the need to have an artificial storyline orchestrated by Game Masters. When players are allowed to fight and take part in large-scale conflicts, they tend to write their own stories. This notion is very appealing to game developers, which is why newer games like Shadowbane are so PvP-centric.
Players purchase new editions every couple of years and game companies make gobs and gobs of money.
In order to keep PvP interesting, a game must depend at least somewhat on player-skill. If a game depends entirely on character-skill, it falls into the previously mentioned pitfalls of maxing out a game s potential. The point then becomes to pick the best class and reach the highest level and when that happens the game is effectively over. Since players can adapt and overcome and develop new techniques of combat, the more a system depends on player-skill the more likely it will live a long and healthy life in the gaming market. Player-skill is more than just taking the outcome of combat out of the hands of some predetermined level system and into the hands of the players.