I don't understand. What do these coupons do? Are they for 10% S3 purchases? Or for the 7.7% back on unit's purchased because of the reduced hashrate?
I got the coupons, because I bought some S3.
You can buy S3 and save 0.015
Coupon value=0.075
I sell coupon 0.06
You save with the coupon 0.015 for each S3.