You've got to be a member of the bookstore's free loyalty program called Borders Rewards to be able to use either the in-store or online coupon. This coupon is also valid at Borders Express and Waldenbooks. Online the coupon expires at 11:59 p.m. PST May 10.
Caveats: cannot be combined with any other offer, promotion, sale pricing, coupon, or discount, including group discounts. Excludes previous purchases, special orders, shipping, gift cards, coupon books, newspapers, magazines, comics, eBooks, digital downloads, vinyl LPs, Smartbox products, Rosetta Stone® software, tax software, video games, and all electronics.