Along those lines I know there is a very lucrative black (maybe more gray) market in which people will pay big money to find out flight plans of important decision makers. People paid that money so they could try to buy a ticket in the seat next to said decision maker. You've then got X hours to work a pitch.
I know this happens to execs in pro sports a lot (people trying to get sponsorship, get the leagues using their products, etc) and I imagine it happens in other industries as well.
How you make a startup/product out of this I don't know but I thought it was an interesting tidbit to share.