the 50% coupon is irrelevant to the issue...it was more of a "we're sorry" gesture and will encourage people to keep rather than return their purchases. in any case, if you pay $60 for a product and get a 50% off for a future purchase, that pretty much means you're paying $90 for two items...i'm sure Graft is still well in the green by taking this route.But the problem will not be reoccurring, they also addressed the issue in a prompt manner. They also handed out 50% coupons to future products as well, so that in essence with the adhesive is a solution not a band aid fix.
the way i see it, the skin is like when Apple gave out free bumpers post-Antenna-gate. it's a work-around for an existing problem, not an actual fix to the design of the product itself.