For most of my life, I read short stories from two sources: anthologies and magazines. If you were a famous writer, like Isaac Asimov or Stephen King, publishers were willing to put out a collection of your short stories or include them in an anthology of short stories along with other famous writers. Otherwise, your best hope of publishing a short story was to submit them to magazines. I took that route. However, with the popularity of the Internet and factors, many of these magazines died out. Most of the ones I read when I was a teenager no longer exist. Even ones that I submitted my stories to ten years ago aren't around anymore. It looked like short stories were dying.
Then along came e-books, and now I'm seeing more and more short stories being published. I should know, since my first self-published effort was a short story collection, Numbers Plus Four. Since then, I've read more and more short stories in e-book format. It helps greatly that you can buy an e-book for 99 cents or even for free, because I personally wouldn't pay $5 for a short story, but 99 cents is reasonable. In the past year, I've read dozens of short stories, most of them by indie authors who I would never have read if not for e-books.
I predict that the flexibility of e-books and e-book pricing will make short stories increasingly popular. If nothing else, authors will release free stories as samples of their work in the hopes of attracting new readers. It's an idea that I'm toying with, as well as releasing another short story collection later this year.