People might already know this, but I'm no fan of marketing.
People are very social animals, and we respond very well to group stimuli. I know I'm part of a group, because I engage in the same behaviors as other people in that group. Being part of a group is a good thing - it helps steer us away from potentially dangerous activities "Should I eat that? Nobody else is eating it..." and guides us towards behaviors which the group will reward us for.
The previous paragraph might seem a bit cynical, but it's not meant to be. I honestly appreciate the normalizing rationality of social norms. We could probably use a bit more of that these days.
But marketing, in general, twists this innate desire to be part of a group. Marketing creates new groups for us to belong to - groups defined by the products marketing wants to sell. The three biggest groups created by marketing are the clumped divisions of age, gender, and income level. Products (ads) targeted at kids are fundamentally different from products targeted at teens. If you study marketing, you'll see that those differences aren't in the complexity of the ads - the differences are primarily in the visual and contextual cues which identify to viewers which age group is being targeted. It's not just about selling products - it's about allowing people to identify as belonging to specific groups, and learning the cues which tell us a particular product is for us.
Marketing and Video Games: 1979 - present
Video Games, for whatever historical reason, were initially marketed at men age 14-30. For 30 years or more there has been strong research showing that women and older adults also buy and enjoy video games, but the marketing brand associating video games with that demographic was so strong that nobody (almost nobody) ever really tried to expand that market. Nintendo's Wii broke down huge barriers by drawing in a wide demographic - but even today Sony and Microsoft keep their eyes squarely on the "core" demographic of 15 years of a boy's life.
But right now, today, we have a fantastic opportunity to redefine the core of video game players. And we can do it without regard for age, gender, or income level. We've been predicting this shift for decades, but it's actually happening right now. We're over the tipping point. And why?
Because mobile games aren't marketed.
Lots of people complain about the lack of visibility within the App Store, or about the shifting targets of expected product quality. The app store is a wild-west anything-goes place right now. And because it is still evolving, the apps themselves aren't subject to the rules of marketing that we've all grown up with. iPhone games aren't for "gamers" who own phones - they are for everyone who owns phones. And what kind of people own phones? Everyone. We're seeing a lot more honesty, creativity, and good value coming up from the app store - and I think a lot of that is due to the lack of social structure. There are very, very few games on the app store plastered with pink in order to appeal to women because women aren't a special audience - they are part of the core audience.
We're also moving to an entirely "freemium" based economy within the app store - where people evaluate your games based upon actually playing them - rather than reviewing the marketing materials. Games are finally standing on their own merits instead of being lumped in with a social group's "gotta have it" litany of objects to purchase. And that is all for the good.
The New Demographics
The most important demographics are now about behavior and expectations - just like the demographics in books and film. You don't ask somebody you're just meeting "do you like to watch movies?" because you know that everyone likes movies. The question you ask is "what sort of movies do you like best?" We're getting to that level where people don't define themselves as "gamers" (14-30 year old men) or "non-gamers" (everyone else). Rather, people define themselves by organically describing their ideal game experiences. People might be puzzle gamers, or enjoy western-genre games, or seek out historical simulations.
So how do you leverage this new playing field in your own game? The simplest way is to define your target audience by listing the qualities that you feel your game will satisfy. "Our audience is people who like exploration, rubies, and hospitals." Perfect. You'll not only connect more robustly to the people playing your game, you will sleep better at nights.
Another new way to define your demographic is to let your actual customers define it for you. Metrics, forums, mail-list and the like can all serve as direct feedback conduits, letting you know exactly who is playing & purchasing your game, and why the like it. (Or don't.) It's hard to automate these channels, so supporting them requires significant personnell investments by your company - but it can build fanbase at an incredible rate, and as a long-term strategy fans are more important than sales.
Even if you can't invest in personal communications with your customers, the fact that other companies are is giving fans a sense of self-determination which makes this entire effect snowball. From my perspective, the apps community has created a sales plan which emphasizes product reality over marketing fantasy - and that's a win for everybody.
Unless you're in marketing.