I think it's a tough sell from the player side. I mean if I'm a player who wants to buy fortune cards I have to get the DM to sign off on it first and foremost, and he's probably going to wonder what the other players will think of my character getting a small but tangible boost because I purchased something extra from WotC.On second thought, maybe that's not the case, and here's why:
DMs buy counter packs. Fortune cards are targeted at players. We all know which group is larger. Whether players can be convinced to buy the cards is another matter entirely.
I guess it would be an easier sell for everyone if you just bought a case and shared them with the other players.