What: Shares of Barnes & Noble (NYSE:BKS) were down 20% as of 11:00 a.m. Friday after the bookseller reported weaker-than-expected fiscal second-quarter 2016 results.

So what: Quarterly revenue fell 4.5% year over year to $895 million, well below analysts' consensus expectations for revenue of $917.8 million. That included a 31.9% decline in NOOK sales to $43.5 million, due mostly to decreases in content sales, and a 3.1% decline in retail sales to $861 million, driven by a combination of store closures, a 1% comparable-store sales decline, and lower online sales. Excluding NOOK products within the retail segment, retail comparable-store sales declined 0.5%.

Meanwhile, Barnes & Noble generated an EBITDA loss of $20.5 million, including a $10.5 million severance charge related to its previous spinoff of Barnes & Noble College. Excluding that severance charge, EBITDA loss would have been $10 million, or a roughly 28% improvement over the same year-ago period.

On the bottom line, Barnes & Noble's net loss came in at $39.2 million, or $0.52 per diluted share, while its net loss from continuing operations was $27.2 million, or $0.36 per share. The latter figure includes an $0.08-per-share impact from the severance charge. By comparison, analysts' estimates called for a narrower loss from continuing operations of $0.31 per share.

Now what: Nonetheless, Barnes & Noble reiterated its full fiscal-year 2016 guidance for Retail core comparable-bookstore sales to be roughly flat from fiscal 2015, while comparable-store sales excluding NOOK products are expected to increase 1%.

In part, it seems Barnes & Noble is banking on a solid holiday season. Through Black Friday, the company noted third-quarter comparable-store sales excluding NOOK increased 1.1%.

As Barnes & Noble CEO Ron Boire elaborated, "This holiday season, Barnes & Noble executed large-scale, nationwide events to create excitement and drive traffic to our stores. Barnes & Noble's buyers and merchants have curated an outstanding selection of books, toys and games and gifts, and our booksellers are prepared to help customers find the perfect gift for everyone on their holiday shopping list."

In the end, however, the fact remains Barnes & Noble's NOOK segment is proving more than anything to be an anchor for its already struggling core business. With virtually no positive news in this report, and until Barnes & Noble can prove it has what it takes to claw back to sustained, profitable growth, I think investors would be wise to avoid the stock.