I'd love to see sub and renewal data like this for "indie" or small shops making an MMO or other on-going, recurring revenue games.
I mean assuming you can keep roughly 1,000 people subscribed at $5 a month, then each year a game would pay out $60,000 dollars. If you get a loyal fan following then this would be a great revenue source. Once people are emotionally tied into a game then it can often keep them in the game for many, many years.
If you could keep a lot of the heavy work on client-side (not unreasonable for modern computers if you're producing a non-CPU intensive game by nature) so that your bandwidth and server needs stay low, then once you break-even you'd hopefully be able to keep a large chunk of that $60k.
Correctly done, I imagine an MMO could quite possibly be the best way an "indie" developer could make big money without a publisher taking a huge cut. I mean sure if you can get a publisher to sell the game for $20 or so and let them take most of it to help grow your users, but keep the monthly fees in your pocket.
ed: the biggest issue with an "Indie MMO" is that maintenance costs can make it a non-indie kind of venture very quickly.
If you are including text based games, there is a lot of competition, but you can be successful. I played Kingdom of Loathing for a few months, and it was a profitable mmorpg. That was even entirely free. Donations were accepted, and got you special items, but those items were traded on the in game market for in game currency.
Installing new games and learning how to play them is work. Making a game you already like be bigger and better could be a profitable business.
Done. It's called 2nd life.
There is nothing stopping anyone from creating games in 2nd Life. It's exactly what you asked for mod tools. It's all mod tools. It's all up to you.
Games esp mmo's are mostly socializing.
It's just a world. Geez, only a world. Like saying its just reality there's only sticks and rocks here, no games. Pick up the damn rock and hit it with a damn stick.
Have a modicum of imagination.
The quality of Eve Online with it's dozens and dozens of devs/designers/artists/writers and multi-million budget only costs ~ $11/mo.
Micro indie's such as OA can't afford an MMO. MMO takes an order of magnitude or more resources to develop/maintain than single player one-shot. Old Ultima Online is the "level" I'd expect for an "indie" MMO and that took a lot more than an indie level effort to produce/run.