I've been a supporter of Xbox Indies since beginning, and sorry if this sound harsh..but they need to be delusional to expect make a living based on indie games.
Is like some are making games with the hopes of becoming the next Angry Birds, or (as far as Xbox Indie games goes) the next "I Made a game with Zombies in it" (don't know the exact typos
)...
As this gen has show, not even good retail games are selling well with tons of advertising and good worth of mouth, and sadly the mentality of most console games when it comes to digital distribution is a big "DO NOT WANT_DOG.png*; even on a forum like this with many "hardcore gamers" Xbox Indies are ignored left and right, and indies in general; since many jump into indie games when either: the games are on Steam; or the games are on Steam AND on sale. ..or the usual "humble bundles" and the "pay what you want" kind of deals.
And I could be wrong, but the whole idea and concept of making indie games its to make this "experiments" that under normal circumstances publishers would just ignore if they went through the regular channels. Of course we all dream on making it big and be famous and earn profits; but nothing comes from nothing. If you make a game for Xbox Indies and is not as successful as you wanted; keep an eye out for criticism, look for other channels and ways to get the game out, talk more about it, spread the word about it.
There's no secret recipe for success on indie "anything" (games, movies, music) and more of a combination of perseverance, losing a lot of money and still love doing what you do.