One of my orders was 4/11, so I figured I would get at least one coupon. I guess I would understand if Bitmain didn't send a coupon for my 3/21 order, even though it is just a bit more than a month old. If I get one coupon, I will order one more S1 if they send 2 coupons I will order 2 more S1s...If I get none and I know that others have gotten coupons for older orders, I will question whether Bitmain has their act together or not.
I purchased an Antminer S1 on 4/9/14 and sent Bitmain an email asking if I would get a coupon and they said that "yes, coupons will be ready soon".
So I'm confident that I'll be getting a coupon soon.
So far every time I sent an email to them they've answer me within a few hours.