Not too long after 3.0E was released I was working at Hasbro's ad agency and, through a series of circumstances, ended up working on Wizards of the Coast's advertising for all of their products. I was in charge of their media planning (Cliff's Notes Version: we are in charge of figuring out
who to reach,
when to reach them[/b],
how often to reach them, and all at the
most efficient cost).
At the time, I was really jazzed to be working on it and I really thought that there was an opportunity to market D&D to a much wider audience and get it the recognition and the player base that I think it deserved. I was all in favor of more mass-market magazine ads (they actually did run one in
Maxim) and that kind of thing.
Looking back on it now, I'm not sure that mass marketing D&D is the way to go. I do think about this quite a bit considering that the two things I spend the most time doing are my job (I'm still in media planning) and playing/preparing for D&D. Anyway, my thoughts of the top of my head:
1) Part of the problem is that role-playing games aren't a very widely known phenomenon outside of the gamer community. Any mass-marketed D&D campaign would need to involve some level of education about what an RPG is, and that takes away from the core message of trying to sell D&D. Hasbro/WotC struggled with this a lot at the time.
2) Mass marketing campaigns are very expensive. WotC has done quite a bit of research on who exactly plays these types of games - Ryan Dancey even posted their survey results (and I have a copy somewhere lying around). Anyway, the idea is that (and I'm going to make the numbers up, but they're probably relatively close) out of any 10 people that you'd talk to in the "core demographic" for D&D (let's say young men ages 18-34 or something like that), less than 1 in 10 is really going to be interested in playing or running a D&D campaign. Don't get married to the numbers, just follow the idea. I think we can all agree that it's a pretty specialized hobby, takes a fair amount of time, and just doesn't appeal to a lot of folks. That leads us to...
3) "Fish Where the Fish Are". I can relate to this since one of my primary job goals is to acquire awareness of my client's products at the most efficient cost possible. The idea is that, rather than blanketing a lot of people and seeing what happens, instead you just target people that you're already pre-qualified as being interested. When the D&D game was first invented back in the early 70s, many (most? all?) of the first players were actually miniatures wargamers. They had an interest in games and gaming and in the more strategic type games, as well as some of the more esoteric ideas like an ongoing campaign and that kind of thing. Those first games were acquired with very little (probably no) marketing dollars spent. And, they told their friends, and there you have the beginnings of the hobby. It's much more efficient that way.
The ROAS (return on ad spending) is much higher for WotC when they just advertise the latest release online on fansites and gaming sites and in gaming magazines. Sure, they're limiting their potential audience, but they are talking to people whom they already know have an interest in the topic and are eager for news on the latest product releases. The sales per dollar spent is much higher than it would be if there were to advertise, say, the Basic Game in something like
Boy's Life magazine.
The downside, of course, is that you rely on your existing players base to generate new players through word-of-mouth. That's an inexpensive and efficient way to get new players, but it limits the overall public's awareness of the game. It's easier to be talked into buying something if you've heard of it before than if you haven't heard of it.
I've a few ideas, but I'm on my way out the door to a nice dinner with my wife.

The ideas involve talking existing younger player bases (from CCGs and such) and coming up with some kind of interim CCG-RPG type hybrid thing that kids would learn about, and then graduate these kids into full-fledge RPG'ers. Just a thought...