Couple of quick ideas I thought of heading home on the train. If you can create these you might be on to something.
Universal avatar system where you sell virtual goods,
– create an extendible personal avatar system for flash games that allows the player to earn new items for their avatar based on game play.
White label social games.
– allow brands to create their own Farmville. Create an SDK (development kit) where companies or amateurs can create new worlds. Think Minecraft/Lego meets Zynga.
AdSense for virtual goods,
– standardize virtual goods so that advertisers can upload into a system and allow players to buy or place in their own virtual worlds.
That’s three and none of them are easy. They are just ideas that some company either has done I didn’t see or will do soon.