A high school student I know finds the Khan videos not deep enough. She said they are a good introduction but didn't cover anywhere near what she was seeing in class. So I guess you get what you pay for.
Not enough meat to cover the legal, accounting, and other costs. Hey, lifestyle businesses can be fun and good to the developer. If it isn't fun then there are some hidden costs and hassles that would make it even less attractive. Maybe someone could bundle a bunch of these and sell it like mortgages ;>}
Interesting, I feel for "trained" users who use directed graphs for work this is a valuable technique. But even the researchers admitted it is not obvious which way the flow goes. So I don't think it would work well for advertising or public presentations.
The research paper makes interesting reading, and how often can you say that!
That appears to be a Lantronics XPORT, been using them for over 7 years. Interesting they are selling them for over 200 we buy them for 70 each, Now that's markup....
Insurance in general is an impediment to entrepreneurship. I know our insurance costs are way more per unit than those of larger companies. I don't know if the higher costs could be attributed to the marketplace or the fact the larger companies are much more sophisticated in their risk management.