Just an idea that will probably have been thought about already, but what about on certain Nintendo Wii games offering a points system for high scores/winning etc and then having a way of converting them into points to buy virtual console games. Nintendo wants to draw gamers in and most people enjoy things by association (e.g. some crap Britney Spears song is played for long enough on the radiio it becomes catchy and people rush out to buy it). By encouraging people to play hard at their games they are likely to raise appeal for their main breadwinning products, full wii games.
Or is is a stupid idea.