Is it wrong to do this?

[Xmo]

I preordered Assassins Creed 3 and gotten the Steelbook. I don't usually buy new games and would wait till it gets to a $40 price point. So i gotten the steelbook for free but I cancelled it 3 days later.

When gamestop announced Black Ops 2 posters, I preordered 2 copies to get 2 posters and now I will be cancelling it and put the money towards Max Payne 3

Basically I get free stuffs for preordering and cancelling them later on and keep the stuff. Is it somehow wrong to do in a sense or is everyone doing this also?