During Steve's iTunes for Windows keynote (or maybe it was during the last one at MWSF...) he mentioned that Apple's goal for iTunes was to sell 100 million songs by its first anniversary. Does anyone know how many they've sold up to this point, the last I remember hearing was 30 million (although the Pepsi promotion will obviously help). Is there a website or something that tracks this, or (more specifically) how many copies of a specific song have been sold?