I signed up with Handango (I'm from the UK) and uploaded a game for people to buy for a few dollars for the Sharp Zaurus - it's not made loads of money (okay, I realise now that people don't want another version of space invaders) but it still sold. A bit.
You still have to agree to their Software Partner Agreement, which means you have to offer bug fixes and make sure the code doesn't contain easter eggs and suchlike. They take 25% commision for handling, hosting and payment processing, plus they take a wodge off in tax (and VAT, for some reason - perhaps I should be claiming that back) but they seem to do a fair amount of business.
I think Handango do MIDP games as well. There are probably other distributors on the net.
If I was doing it for a living, and I used Handango (and other distributors), games seem to sell better for Palm and Pocket PC - probably the wider market of users - so you have a choice of MIDP and SuperWaba for Palm - and I guess PersonalJava, or some other third-party Java spin-off for PocketPC. I'd go for SuperWaba.
At the end of the day, games are games are games. It's all about making a fun game, and like you mentioned, selling in volume. Tiny throw-away games in mass volume, just like a hamburger is throw-away food (but then again, it's the distributors, not the producers who make the most money in both cases it seems). Most of the time, the best selling games are just straight single-screen puzzlers (e.g. Bejewelled on Palm).
I've considered doing code-locked shareware - it gets your game downloaded - because it's free - and hopefully people get hooked. Plus people don't mind paying a bit of money for "shareware."
You could also argue that indie games have more personality in them - just look at Jeff Minter and Llamasoft. He did okay. I think in some respects, making software shareware, or some-other "try-before-you-buy"-ware can help. Although I might be wittering and disappearing up my own backside here.
Getting a game on a coverdisk of a magazine - or getting a review in a magazine - would be a good way of getting some free publicity for a game.
I would only consider doing premium SMS / reverse billing if I was a big company with enough cash, and I was sure I had a good recognisable "license" (blerrgh...*shivver*) or good game publicity.
The holy grail would be to cut out distributors and have m-commerce software embedded in games themselves. But that's probably another topic altogether.