On Saturday I got the confirmation email from AMEX for the Best Buy deal, later that day bought $150 in iTunes cards for $110 ($10 gift card and 20% off Reward Zone offer) and this morning I got my $50 back (shows from Best Buy actually not AMEX).
So in the end I got $150 iTunes credit for $60.
Only credit of this deal I haven't gotten yet is the Wake Up John offer for beating the game, need to look into what I may have missed about that one.
In the past Amex Sync promos used to post it as a regular credit, but this year they started using the retailer's name on the credit (if you click the + sign for credit details, it'll show the Amex promo name somewhere in there)
This way you know which retailer you got the promo for and most importantly they don't have to pay full cash back on your purchase
Before: $100 XYZ purchase, $50 general Amex credit, you pay $50 & get reward pts on $100
Now: $100 XYZ purchase, $50 "XYZ" credit, you pay $50 & get reward pts on $50