FullFare: I owned one of the first AAirpasses in the Boston area back in 1989, when the per mile charge was about $0.21. At that time, the contract allowed for 1 transfer during the life of the contract on lifetime passes. You would probably see this in your contract unless they changed it (back then, the cost of an unlimited lifetime AAirpass with companion was $650k)!
I was hoping that with all of the .com crashes, that someone may own one through a company that went bust and was looking top unload it.
BTW - I believe that the contract also had provisions for work stoppage and bankruptcy that were very favorable to the purchaser.