I got confirmation emails on all 10 of my cards for both SBS and the Amazon promo very quickly (probably within the hour of registering). I received all the credits today. The only exception was my one non-Amex branded card (a Fidelity card) where the charges take longer to post in the first place, so it makes sense that the credits would come a little later than on the other cards.
I also did the TigerDirect promo on one card, got confirmation right away, and hoping to get the credit tomorrow (only made the purchase yesterday).