The phenomenal success of the saucy 50 Shades of Grey trilogy has helped Barnes & Noble report a smaller loss than anticipated in its first fiscal quarter. While thousands flocked to its bookstores for the popular Fifty Shades of Grey series, tech-savvy readers snapped up its e-books and other digital content during the period. The double dose of good news, coupled with cost-control efforts and lower expenses, helped the New York company’s loss narrow while its revenue rose. Weak sales of its Nook e-readers and an unchanged full-year outlook may have given investors pause. They sent its shares down more than 3 percent in morning trading. Barnes & Noble Inc., the largest traditional U.S. bookseller, faces tough competition from online retailers like Amazon.com and discount stores as consumers increasingly move away from traditional books in favor of electronic books.  These factors have pushed the chain to invest heavily in its Nook e-reader and e-books, with digital content playing a key role in its success last quarter.