After their great success in selling people a completely equipped level 70 character on an arena server for $20, Blizzard nevertheless received countless complaints that the freshly bought characters were only useable for arena PvP. Battlegrounds and all forms of PvE are disabled on the arena servers. Sensing a business opportunity, Blizzard reacted and will introduce micro-transaction servers: These work exactly like a normal server, only that you can buy various achievements for dollars. There are scrolls that let you earn a level, getting more expensive the higher you already are. Going from level 1 to 60 will cost you about $20, from there to level 70 is another $20. You can buy gold at a very advantageous rate of $20 for 1,000 gold, making an epic flying mount cost $100. And you can buy various PvE and PvP epic, although they are pricey, and a complete set of the best available epic gear will set you back $200. NOT! Blizzard isn't that stupid, they know very well that this business model would destroy World of Warcraft.
I'm only raising the spectre of micro-transactions to show up how the rewards of World of Warcraft lose value if they aren't actually achieved the regular way. You were probably disgusted by the thought that somebody could pay dollars to reach a certain level or get a set of epic gear without playing the game. But the sad truth is that some people do exactly that. There are powerleveling services, honor point grinding services, arena point services, and anything else you can think of. If you wanted, you could create a fresh account, make a level 1 character on it, then give the userID and password plus a bundle of dollars to a powerleveling company, and receive the account back some weeks later with your character now level 70, having an epic flying mount, two tradeskills at 375, and a complete set of PvP epics. Only it costs more than I wrote in the first paragraph, and there is a risk you'd get banned or "hacked" a while later. Alternatively you could spend money on a bot program, and achieve all this by botting yourself, although again you'll most likely get banned.
But the existence of powerleveling services, bot programs, and battleground afkers shows that for some people reaching the reward has become more important than actually playing the game. And that leads to the question whether WoW is too reward driven. As some commenters yesterday remarked, you have to grind boring stuff to get to the fun stuff. Want to do arena combat and actually win occasionally? Well, you better grind battlegrounds for resilience gear first. Want to travel faster? Grind gold for a mount. Want to see new dungeons? Grind the old dungeons for gear first.
Imagine that once you leveled up to level 70, you could get a set of blue gear with useful stats for your class relatively easily by various means, and that this was the best gear available in the game. No raid epics, no PvP epics, nothing. It would mean that if you entered an arena, you'd be sure that your opponent had exactly the same gear as you do, and suddenly the whole system becomes skill-based instead of gear-based. It would mean that all raid dungeons from Karazhan to Sunwell Plateau would necessarily be much closer to each other in difficulty level, and your guild could go raiding whereever they wanted, just based on your skills in beating the various boss encounters, not on your gear. The only rewards would be things like titles and trophies.
The reason why neither micro-transactions nor a skill-based, gear-free World of Warcraft will ever happen is that Blizzard is earning more by having this reward driven system, where every reward takes even longer to achieve than the previous one. You ARE paying Blizzard X dollars for your epic mount, only you do it in the form of monthly fees and the weeks it takes you to gather all that gold. By making the final rewards insanely hard to achieve, Blizzard guarantees that 99%+ of the population never gets there, and keeps spinning the treadmill, always creating revenue for Blizzard. The system isn't designed for maximum fun, but for maximum profit. Players "outsourcing" the grind is a sad consequence of that sort of game design. Maybe selling us those epics outright would be the better solution after all.