Updated on December 10, 2021
Marvel’s announced that they’ve stopped selling single-issue comics at Barnes and Noble and Books-A-Million:
http://www.comicbookresources.com/?page=article&id=49951
I suppose I can’t blame Marvel for pulling singles from bookstores, though their trade paperbacks will still be sold at such venues. While some suggest digital is the better alternative, I think the existing singles business model’s broken. Who (outside of enthusiasts) wants to pay $4 for a 22-page story that’s only one part of a multi-part storyline? The single-issue superhero comic as it currently stands is probably the least cost-effective form of entertainment. By contrast, trade paperbacks are a better deal, actually contain an entire storyline, and fit on a bookshelf (versus requiring specialized storage).
Superhero comics are also competing with their own corporate cousins—the various video games, TV shows, movies, etc., all of which provide more cost-effective forms of entertainment. Video games also have the advantage of letting you become (virtually) your favorite superhero, as Scott McCloud noted in his books.