People are going to pre-order far more from game spot anyway because of the kratos sackboy inclusion
out of all the stores amazon gets the worst preorder bonus (my opinion). a mini digital strategy guide which if pc based will be available to anyone over p2p networks, or if locked to ps3 will likely be available on the pc as screenshots.
gamecrazy gets a burlap sack for game case storage with sackboy artwork.
gamestop/ebgames gets kratos sackboy
circuitcity gets a littlebig sticker book
and ???? bestbuy/futureshop/walmart gets a nariko sackgirl by default (hasn't been announced but are the only major stores left)
+ as always amazons chartz have little relation to whats actually happening in the market.