Nook sales fell more than 22% in the fourth quarter to $87 million for the three-month period ended May 3. Device and accessories sales in the Nook segment were also down -- plummeting 30% to $25 million in the quarter. Barnes & Noble blamed lower selling volume and discounting for the sales decline in the period. Moreover, revenue from digital content was $62 million in the fourth quarter, down nearly 19% from a year ago. Results from Barnes & Noble's retail business, on the other hand, were a bit brighter.