NCsoft's and ArenaNet's Guild Wars, the only online roleplaying game that has managed to win over a huge amount of former WoW junkies and PvP [Player versus Player] fanatics has now sold over six milion units.
There are many factors that contributed to this great success. One if not the most important one was free playtime. While you have to buy the game itself the gametime itself is completely free - a combination of conventional playing games model and an refreshing change when it comes to the world of MMO titles. There are many free to play games out there each with their own trick to get money and minuses for free players. Guild Wars broke this mold with great gameplay and beautifull graphics never seen in a free to play game [and even some pay-to-play games, Ed.] proving that you can have your cake and eat it too.
Bring your daughter to the slaughter :)
System that Guild Wars used to optimise their servers was instance zoned areas. Loved by some hated by others and just poorly done in some other MMOs it would put players together in cities yet created separated playfields for individual parties. This made game world huge and enjoyable yet lag-free. The only downside was that you could not meet anyone randomly outside of city and some players loved that.
Level limit of 20 was a good way to keep the game in check and create a experience less frustrating then "ooh I must grind this 100 levels to become uber" character level design. Expansions that offer leveling from 1-20 in whole new zones are also quite interesting feature compared to some companies that still think that adding 10 more levels to the existing cap (level limit) and calling it a night is good enough.
But all that is icing the true secret of Guild Wars is its PvP mode. In here no amount of leveling or leet gear can make you a PvP good who kills everyone by rolling his head on keyboard. Everyone has an equal share of good skills and armors who do not have massive statistic bonuses. In fact all high level armors are the same in quality and the only thing money can buy you in regard to them is mastercrafted look. Great thing for PvPers was an ability to create arena only character who does not have to spend a minute of time doing PvE [player versus environment] if he does not want to. This is a feature that Blizzard later unsuccesfully copied with their Arena Tournament servers which are sadly not available to players from all countries.
To celibrate this succes and fourth anniversary of Guild Wars ArenaNet has relased a major content update, including new quest content and extra storage options. At the time of writing [early morning April 29] additional in-game birthday festivities begun to reveal a little bit different morning in the virtual world of Guild Wars.