Getting away from your core competency
So I (used to) go to Barnes'n'Noble a lot to browse & buy books. It was a lot easier than browsing Amazon and much better for finding stuff I liked but didn't know I liked which is pretty much impossible to search for on the net.
They had a big selection of interesting books.
Now they have a tiny selection of mass-market popular books, and toys, puzzles, a coffee shop, DVDs, CDs, a large Nook sales display, several huge racks of magazines I can get in the grocery store, a half-store "multimedia" section that no one visits, and tons of other shit taking up space from selling interesting books.
For example, I'm 90 miles from Kennedy Space Center and 30 miles from Walt Disney World, yet they don't even have any space/astronomy/science books and very little Disney stuff any more. I know that used to sell, because when they had it, the employees I knew said it sold well. So why don't they have that any more?
This is why they're going out of business.