there aren't even more than 2000 people playing. even if half bought it, which would never happen, thats not enough. once you buy a map pack you can only play with those that own the exact same packs. if a friend doesn't have them, or another friend has all 4 and you only have 3, none of you can ever play together again. i think you can imagine what this would do to a playerbase of less than 2000.