I play WoW about 20+ hours a week (Selecta on Spirestone) and I have played through most of the pre-expansion pack content, so let me comment on this from personal experience.
Things that make WoW successful are part of many good games:
1) Feelings of accomplishment - you come back to a character every time that you yourself built up. The persistent nature of the game (rather than a first person shooter where every game is a blank slate) is compelling.
2) Working with others to achieve a common goal - it's fun to team up with people and take on hard bosses that none of you could defeat individually, or even in smaller groups. The later stages of the game feature god-like foes that require dozens of people working in very, very tight cooperation to defeat, or else everyone will certainly be killed (Sunwell Plateau, etc.). In other words, 50 people randomly banging on the harder bosses will not suffice because the bosses are so powerful they can simply divide and conquer. It really is challenging.
Many games have those qualities. What makes WoW better than them?
Well, basically WoW corrected a lot of EverQuest's flaws. That's basically it. They had the second-comer advantage in that. It had Blizzard's name behind it, too (Starcraft, Diablo - both highly successful franchises in their own right).
Plus, there's a real in-game economy, with a value-added chain and everything (gather or buy raw materials -> turn them into a valuable item -> sell the valuable item at a higher price than the cost of the materials). The game's currency is valuable even up to high levels in the game (although there are many guilds sitting on hundreds of thousands of gold with nothing to really spend it on -- it doesn't scale that high). But, it is definitely valuable to have thousands and thousands of gold.
You can't easily "replicate" something you have absolutely no comprehension of.
Don't fucking try to treat it like a business application, because it isn't.
Things that make WoW successful are part of many good games:
1) Feelings of accomplishment - you come back to a character every time that you yourself built up. The persistent nature of the game (rather than a first person shooter where every game is a blank slate) is compelling.
2) Working with others to achieve a common goal - it's fun to team up with people and take on hard bosses that none of you could defeat individually, or even in smaller groups. The later stages of the game feature god-like foes that require dozens of people working in very, very tight cooperation to defeat, or else everyone will certainly be killed (Sunwell Plateau, etc.). In other words, 50 people randomly banging on the harder bosses will not suffice because the bosses are so powerful they can simply divide and conquer. It really is challenging.
Many games have those qualities. What makes WoW better than them?
Well, basically WoW corrected a lot of EverQuest's flaws. That's basically it. They had the second-comer advantage in that. It had Blizzard's name behind it, too (Starcraft, Diablo - both highly successful franchises in their own right).
Plus, there's a real in-game economy, with a value-added chain and everything (gather or buy raw materials -> turn them into a valuable item -> sell the valuable item at a higher price than the cost of the materials). The game's currency is valuable even up to high levels in the game (although there are many guilds sitting on hundreds of thousands of gold with nothing to really spend it on -- it doesn't scale that high). But, it is definitely valuable to have thousands and thousands of gold.
You can't easily "replicate" something you have absolutely no comprehension of.
Don't fucking try to treat it like a business application, because it isn't.