I'm sure some people have only pre ordered to try the beta to see if they like it or not. Now some of those people will hate the game and not get the full version. On the flip side though, people who pre ordered only to try the beta as they have no idea what Destiny is might love the game and in turn decide to buy the full game. I for one only started to care about Destiny once I played the alpha as before that I had no idea what this game was or what it was about. So I think the pre order numbers for this game are about right for how many people will buy the full game, as like I said some wont buy the full game as the beta didn't impress them and some will change their minds and end up buying the full game because of the beta.