It's been a tough spring for the retail book business.

Chapters Indigo announced Tuesday that after 15 years its massive store at John and Richmond will close at the end of the month.

The store is just the latest in a long list of Toronto brick-and-mortar book retailers to fold up shop in recent weeks (see map above or click here if you're on a mobile device).

Mark Medley, National Post books editor, spoke about the trend in an interview with Matt Galloway on CBC Radio's Metro Morning. Medley said six Toronto book stores will close within the space of six months.

"That Chapters is considered the flagship store in the Indigo monolith. It's been there since 1999 and it was always my bookstore coming in from the suburbs."

Galloway asked if book lovers should mourn the loss of the Chapters, which may have played a role in the demise of Pages, an independent bookstore nearby at Queen Street West that closed in 2009.

"If you had asked me five years ago whether I'd be mourning the death of a Chapters, I would have said you're crazy," said Medley. "I think we have to hold on to every one we can."

Medley said more and more book buyers are making their purchases online.

"You could recommend a book to me right now and I could download it on my iPhone or my tablet within 30 seconds without even leaving the studio," he said. "We don't have to go to bookstores anymore."

He said the consumption of books isn't waning, but it is changing.

"People aren't shopping for books in the same numbers they used to and they're shopping for books in different ways," he said. "The economic reality has kind of set in here."

Galloway asked if Medley could see a near future when the city has no book retailers downtown. Medley said the trend is more of a "right-sizing" that reflects the shift to online buying.

"The city of Toronto may only be able to support three or four bookstores, but hopefully they'll be three or four good book stores," he said.