Or "Let's give 'em something to talk about".
It's lately been in vogue to trash World of Warcraft, and it's no new thing that something popular should be heavily criticized. When you reach a certain level of visibility you draw fire from people who like to rage against The Man and from people who don't dig the trend and therefore get irritated by being reminded of it. Similarly, WoW has been talked to death and it becomes difficult to put forth any analysis on something so heavily discussed. But I think there are still important things to talk about vis WoW's insane success (and when a single game gets big enough to
buy Activision, it is insanely successful), and it also reflects on the successes of major popular fiction titles as well.
Something that WoW did almost by accident -- and I do think it was by accident because nothing in their engineering supports this specifically -- was create a social context. Raiding parties do this naturally, but WoW did it particularly well. It actually brought people together, friends that I know who hadn't talked to each other in years, who are suddenly now talking every day and engaging in a virtual environment. It strengthened old friendships and forged new ones. Online games have a history of connecting strangers, but WoW, unlike its predecessors, connected people who already knew each other, gave friends something to talk about and something to do together -- questing in WoW became as much a staple as going out to a movie or restaurant. And for the interconnected but geographically separated populations now currently bridged by technology, that became even more important.
It did this for strangers, people applying for jobs, people in waiting rooms. WoW got so big that you could mention playing it in some non-game-context social environment and stand a good chance of someone, rather than looking at you like you were a space alien, asking what server you played on, what profession, and BAM, off you go into a detailed, often impassioned conversation with a total stranger.
This is part of a core purpose of entertainment media that isn't frequently discussed. The form that did this so pervasively that it's now a cliche ("So how 'bout them Padres?") was baseball. I heard a story on NPR some weeks ago, a retrospective on the removal of the Dodgers from Brooklyn to Los Angeles, and how, in Brooklyn, it utterly removed a social context from the streets of New York -- literally made the city a more unfriendly place.
And now MMOs are filling this purpose. But fiction did it too -- Harry Potter operates on a similar level, and actually for similar reasons. Jordan's Wheel of Time would have done something similar had it ever really broken out into the mainstream, which it nearly did, but not anywhere close to Rowling's achievement.
What all of these have in common -- and I have to waive the bias flag here just by disclaimer, in case you missed its obvious presence in my worldview -- are game mechanics. They vary in things like their specificity of discussion -- WoW discussions tend to be strategic or exploratory while Harry Potter discussions are mostly speculative, trying to guess a plot's next movement (and therefore, I think, HP discussions are more limited) -- but the connecting element between these hugely popular epic works is the very mechanical way that a viewer of the media is able to connect with the work. When we read, I believe we are subconsciously -- or often consciously -- slotting ourselves into the world. It is part of the immersion. And so if there is an easy character class for us to identify with, we have a hook of fascination that makes that immersion much more vivid. Games do this overtly, asking you to choose your poison right from the beginning -- books are a little more subtle, though Wheel of Time certainly was about as subtle as a brick to the head with its character classes. Harry Potter was a bit moreso with its wands and various subtle breeds of wizards, though they all studied in the same place. The most overt class-generation there was in the House structure at Hogwarts. But it is certainly no coincidence that there was a huge flurry of marketing attention devoted to the concept of "What House would You Belong To?" It encourages the fantasy.
In essence when you are socially connecting via or over one of these media, you are expressing your personality. Personal expression is key in any kind of social gaming (and any personal interaction can be termed social gaming on some level). When I'm talking about speccing out my Hunter and what kind of pet I want to go after once I hit level 40, I am really talking about personal expression, elements of my personality that are not easily conveyed but take symbolic form in these game mechanics. Likewise for a kid who says they are certainly Ravenclaw and could never be anything else in the Harry Potter universe.
What this means in terms of world-building, for any media, is that completeness is important. Properties that have fallen short of the mega mark, but otherwise had that kind of potential, often lack completeness, something that they could have arrived at through theories applied in video game mechanic balancing. The D&D character class structure is a symbolic and evocative version of the same thing Myers-Brigg were trying to do with their type indicator -- and if you go through and make sure that you have a character class for each personality type (and I'm not saying you should use Myers-Brigg -- they're not nearly creative enough, though it would be interesting to see someone try), you're that much more likely not to lose parts of your audience by not giving them a place to slot themselves in the world. In Wheel of Time, if you were female, you were basically Aes Sedai, royalty, or boring -- and I would bet that was a partial audience turnoff.
In essence, I believe the principles applied in game design to generating a complete player experience -- which at its core is a meta-layer, a fictional world that is whole and satisfying, a full layer on the real world in which we exist that you then push one degree farther to see what happens -- can be applied to any fictional work. And the great thing is that when you engage in this kind of elegance-focused worldbuilding (I say 'elegance' because that, in a computing sense, is what you are attempting to achieve when balancing character classes -- you need to be complete without going overboard and having so many choices that the reader can't connect), you're also creating a more realistic world, because you are taking into account elements of fantasy not just sprung from your own mind, but ones that you might never consider a reader (or player) wanting to experience.