Good point about advertising where the players are instead of where the developers are.
Sometimes I ask myself if just a bit of promotion is enough for indies. An outstanding game will be recommended by word of mouth. If 10 people play your game and it doesn't snowball and get popular, then it would probably also not be popular if promoted heavily because it's not that good. Cream always rises to the top.
On the other hand the big companies often put as much money in advertising a game as they put in making it. But those are usually big studios, maybe it's different with indies because they usually are not tailored for the mainstream.