This is a big ploy to get people to do a big download before they're sure if they want to buy, as well as to ensure simultanious availablity to maximise the number of purchases that will be made before anyone can play it long enough to bad-mouth it. For the pre-loaders who weren't sure, the reviews will have to be pretty bad for them to just dump that DL that took them days to obtain; in the end, they'll pay.