UPDATE: So the deal with this coupon, evidently, is that it IS for real, but you have to pick them up at Borders stores that are closing - they have a stack of them by the register when you check out. Sounds like Borders may not accept copies or you showing it to them on your mobile device, so you may have to swing by your local deathbed Borders in person to get one. But for 50% off, it could be worth it!
Here's a 50% off Borders coupon, but I'm presenting it with a big fat caveat, because I'm not entirely convinced it's for real. We see a lot of Borders coupons around here and this doesn't look like the usual format; even the (very rare) legit 50% off coupons generally have the same appearance, and this one doesn't feel quite right.
If you're feeling brave, take it to your local Borders and see what they say, but my Savey-sense is tingling on this one.