Second - Don't worry, I'm not going to ask the Usual Questions (TM). I know you want to make a multi-player game, I know it costs a lot more than a single-player game, and I know funding for this kind of game is hard to get.
But it did cross my mind (actually when playing a totally different game) that a space MMO would be in a unique position to monetize (is that a real word?) something that doesn't really work in games set in medieval fantasy universes. I'm talking about in-game advertising.
Remember Blade Runner? Remember those huge ads on the sides of buildings and on floating billboards?
Now, in Rebirth you'll be able to walk around inside ships, right? Presumably, also around some space stations? So how about talking to a few advertising agencies and letting them buy (virtual) ad space in the walls and screens of those space stations?
I'm not talking about forcing people to watch ads when they're trying to play the game. I'm talking about ads playing on screens in the background (or on giant billboards floating near planets, etc.), integrated into the game universe, but for real products (possibly mixed with some ads for in-game products as well). Players could walk up to the screen and watch the ad, or it could just be something in the background, adding a bit of atmosphere. Done properly (i.e., supervised by Egosoft, to make sure the ads fit in with the style of the game) they could actually make the game more immersive, just like the giant billboards in Blade Runner.
You could even demand that the ads be for fake (future) products (like "Reebok AntiGrav shoes" or "Mercedes Class X sports shuttle"), and I'm sure a lot of brands would still rush to buy some ad space, as long as they got to place their brand name and logo in the game. Remember the Nike shoes in Back to the Future II ?
If some company was willing to pay a lot, you could even add little scripted sequences inside space stations where some NPCs used the product in question (ex., drank from a can of Coca-Cola, or talked about how much they loved their new Adidas shoes). Again, always in the background, never getting in the way of gameplay.
This is a new market and I'm sure any up-and-coming ad agency would love to be involved, since the traditional markets (TV, radio, street billboards, even website ads) are controlled by a few older and bigger companies.
Has Egosoft looked into this possibility? Was there no interest on the part of marketing agencies? Or is this something you wouldn't even consider because you don't think you'd be able to enforce design guidelines to make the ads fit into the game universe?
Disclaimer: I have worked in some fields connected to media, advertising and game design in the past, but am currently not connected to any company in those fields. I'd be happy to help Egosoft in any way that I can, but my main interest really is having a good space trading game to play, and multi-player tends to make things more varied and interesting.

P.S. - Yes, I know Rebirth is going to be a single-player game, I'm only using it as an example for a future (possible) MMO. Although "funded by in-game ads" could also be applied to single-player games, an MMO would open up a lot more "social" possibilities, such as meeting your friends in the space station bar, etc., which would only make any in-game advertising even more valuable.