Just to add my 2 cents...
People and businesses buy full fare J tickets ALL THE TIME. It's not a unique occurance -- I know plenty of people that purchase full fare J for leisure trips and I know plenty of small businesses that fly their employees in J on international flights. These businesses do not have contracts with major airlines and often purchase tickets close to the departure date.
I also know a few people that purchase full-fare F tickets when flying int'l. It's not nearly as common, but it proves to me that a market exists, esp ex-NYC, ex-BOS, and ex-LAX.