Welcome to FlyerTalk,
flightseat!

^
Very interesting and creative idea, IMO, so kudos to you for that!^
The problem I see is that I highly doubt so many people will do this to the point that there will be many matches. When you think about how many people travel, you'd need a LOT of people to join this (tens of millions) for it to even work a small percentage of the time.
That's the problem I see with it, but I like the idea in general.