Once Borders blew itself up, Barnes & Noble’s future as the chief surviving national retail book chain was assured, right? Well, so much for that idea:

After a year spent signaling its commitment to build its business through its Nook division, Barnes & Noble on Thursday announced disappointing holiday sales figures, with steep declines that underscored the challenge it faces in transforming from its traditional retail format.

Retail sales from the company’s bookstores and its Web site, BN.com, decreased 10.9 percent from the comparable nine-week holiday period a year earlier, to $1.2 billion, the company reported. More worrisome for the long-term future of the company, sales in the Nook unit that includes e-readers, tablets, digital content and accessories decreased 12.6 percent over the same period, to $311 million.

“They are not selling the devices, they are not selling books and traffic is down,” said Mike Shatzkin, the founder and chief executive of Idea Logical, a consultant to publishers. “I’m looking for an optimistic sign and not seeing one. It is concerning.”

As the fourth year of Recovery Bummer drags on, will the last retail chain please turn out the lights — assuming some form of illumination — one that doesn’t cause cancer, if that’s not too much to ask for — is still legal, of course.