The only issue with your scenario is that walmart are buying in...

The only issue with your scenario is that walmart are buying in tens, therefore that would be the reason, If your across 4000 stores, and buying in tens, that will happen, dont take it as a sign that its successful, as there is also a 30% return rate to take into consideration. It will be months before you see if this is successful or not, but they are in there now, we all know whats happened, time to move on and see if they can deliver in the numbers required to be a success.