Practical things I've learned from working on this project:

1. How to construct a simple website without alot of advertisements
2. How to create pdf-format documents without purchasing Adobe Acrobat software
3. I've exercised a lot of stuff I learned in university in a creative manner such as chemistry, physics, stress analysis, heat management, numerical integration. Stuff I may have to use on the job someday.
4. I've learned some completely new stuff I've never been taught in school, such as theory of communications, and telescope equations.

Less practical things I've learned:

1. How big a greenhouse should be
2. That sunlight is better than artificial light
3. Nutrition facts
4. How realistic space colonization is
5. How small the solar system is compared to interstellar space
6. How important a spherical shape is for the future of space colonies

It's a subject that has a lot of top-down generally educational content. I don't get any academic credit for it, but I don't have to tolerate suspiciously bad grades either. Of course I realize that future generations will be able to do the math themselves. At the same time I realize that people aren't born with math skills, and university students today still have to learn the same calculus invented by Newton 400 years ago - it hasn't changed much. Starship Generations might not change much either and might be part of standard curriculum 400 years from now.

As for profitability, I don't know. The space program isn't profitable now, not even a little bit. Even space camp is having problems from what I hear. People who want to start businesses have to worry about the proximity of a market (people who will buy their product). You can't go very far into space without leaving your market behind. If we had a thriving space colony, one that could support its own basic needs, then Initially they may be their own best business prospect....

Just as China and USA are beginning normal trade relations, people on Earth and people on the Moon may have to grow and develop separately for a long time before any real trade occurs between them. This is in spite of the fact that a moon colony may have a great deal of commerce, but still be isolated from Earth. This is why I believe that bootstrapping space colonies is the only way to go. They've got to grow & prosper on their own because constant support from Earth is too expensive.