Am gasit asta pe un forum si m-am gandit s-o postez si aici (deocamdata nu am WiiU deci nu stiu ce si cum):

People tend to forget this website exists if you own the deluxe Wii U! Plus if you buy Kart and redeem your free digital game it counts towards the promo so you'll be assured to have enough points for at least one $5 credit! I already got my credit for Pikmin 3 that I chose for free, and I'm close to another!

You just need your NNID login info to check and see your status!