The funny thing about business plan competitions is how often the "failures" turn out to be massive successes. The one I know of best is Raising Cane's chicken fingers. The business plan was given a C- and then the founders went fishing in Alaska to make the money for the downpayment.
I was once told (in 1987) that the business plan for FedEx had been developed for a class, and it got a C because the professor believed nobody needed overnight delivery.
Summary: The rough idea of using centralized switching for parcel routing was in a paper for a class, but not much else.
Key quote: "in a 2002 interview Smith acknowledged that "I don't really remember what grade I got. I probably didn't get a very good one, though, because it wasn't a well-thought-out paper.""
http://en.wikipedia.org/wiki/Raising_Canes_Chicken_Fingers