Actually, one could leverage existing "points" platforms: give them something nominal in-platform, such as a game or virtual item, but also credit some points of your own. Then partner with many websites to make your points valuable (sharing revenue from the first platform when your points are spent on the websites).
You said the magic words: points are redeemable for money. Congratulations on your entry into international money services! Please send a truck around at your convenience to pick up the relevant regulations. Please make sure your convenience is immediately or we will seize your accounts and possibly prosecute you for money laundering.