  urlLink Yesterday's theme sparked my imagination. I'm not a scientist or an engineer by training, but science is a hobby of mine, and I have a general understanding of the technology and problems faced by folk wanting to go to space.
So, since I only know enough to prove my ignorance (and possibly be dangerous in the right situation "Ohhh, look, red button! Must push button! "), I'm going to engage in wild speculation and create my own fantasy version of the budding space industry.
I suspect the first revenue streams will come from cargo transport, tourism, and research. Carrying cargo like satellites and food stuffs for space station inhabitants will be a preferable alternative. At first, tourism will probably amount to a really fucking expensive carnival ride. People will effectively be paying a few (tens of? ) million bucks to spend a couple of days on a rocket ship. Research organizations will pay to have experiments taken to space where they can be conducted without some of the problems found at the bottom of a gravity well.
As the technology matures and kinks are ironed out there will be some additional revenue streams. One, I think, will be orbital satellite servicing. Satellites only last about five to seven years. Hubble was the first satellite to be successfully serviced in orbit. Had the Hubble not been able to be serviced in orbit it would have been a disastrous (and expensive) failure.
Obviously it is preferable to have modular, serviceable satellites that can be fixed than ones that have to be scratched. It can be compared to getting a new car everytime you need an oil change. Satellites are built more robustly than that, but still a satellite is an expensive bit of gadgetry, and orbital servicing would add some guarantee of longevity. I think companies would pay well for that service (and still pay less than they would if they had to rebuild and relaunch).
Actually, I want my next job to be an orbital satellite technician. If you know of any openings, please let me know. The next step in the industrialization of space is orbital manufacturing, long-term research facilities, and tourist facilities (Orbital Spa and Resort type facilities). The real horse-choking hairball problems show up here. Factories and research labs and hotels require things like air and water and walls. Lots of all of them. Coming up with those things is problematic. Hauling all that stuff up from the Earth is a horse-choking hairball problem by itself. Taping it all together is another. Building an orbital factory will not be a matter of fitting nipple A into Slot B and tightening the universal flangelator.
I think that the best way of building the foundation for an orbital infrastructure would be to build modules here on the ground and launch these fully functional modules into space where they could be stuck together ticky-tack style. Launching the components for a module and then constructing them in space seems inefficient when a fully functional module could be up and running as soon as it is bolted onto the larger structure. These modules would necessarily be smallish and limited in their productive abilities, but they could also be dedicated to expanding the orbital structure.
The factories would be better used to build additional facilities and such than being used to build things for use on Earth. Coming up with raw materials is problematic (though not horse-chokingly so). Bringing raw materials up from Earth is pretty much out of the question. I think there are better sources of raw materials. Near Earth Asteroids and the Moon have loads of raw materials that can be harvested. (Not easily, but I'm making the rules. ) Besides when I'm bored with being the satellite plumber, I want to be an asteroid miner ("There's gold in them thar hills!").
That's it in a nutshell. Stay tuned, though. I'll be considering other.
. .
considerations later. 
