Books Set in Bookstores--Where Do These Fads Originate?

In the past three or four years, there seems to have been a plethora of books set in or around bookstores. I have read at least nine (Midnight at the Bright Ideas Bookstore, The Bookshop of Yesterdays, Paris by the Book, The Bookseller, The Bookstore on the Corner, The Readers of Broken Wheel Recommend, Small Blessings, The Bookman's Tale, and The Storied Life of AJ Fikry)--and two minutes spent on Amazon show there are more.

Sometimes when I notice what I think is a trend or fad (books written in first-person plural, with Shakespeare as a plot device, or exploring alternative futures based on small decisions), I think it's just a coincidence. But I have evidence that this bookshop thing really is a trend: at an author event, Cynthia Swenson, who wrote The Bookseller, when asked about the title of her book, replied that the publisher had told her she needed a title that signaled that the protagonist had a bookstore because books set in bookstores were "hot."

So how do these trends get started? Are people looking at trends in the culture and then writing books to match them? This seems unlikely, especially with bookstores, since all we've heard of late is that bookstores are dying. In fact, the opposite seems more likely--people decided to write books to try to increase the panache of bookstores. Still not probable. Perhaps it's just coincidence--a number of writers for no connected reason write books set in bookstores! Sadly, what seems more likely is that one person has success with a book set in a bookshop, and imitators jump on the bandwagon.

Any ideas?

BTW: Two of the books listed above stand out from the rest: The Storied Life of AJ Fikry, by Gabrielle Zevin, and the recently read Paris by the Book, by Liam Callanan. Paris by the Book is a bit of a mystery--Leah Eady's writer husband Robert has disappeared and she has moved her daughters to Paris in hopes of finding him there. Leah and Robert both love Paris (or the idea of Paris), Leah having been seduced by The Red Balloon and Robert by the Madeline stories. Leah ends up running an English-language bookstore, where she organizes the shelves by location, rather than subject or author. Meanwhile, she and her daughters surreptitiously look for Robert, rarely confronting the question of whether he might be dead. There's considerable sorrow in the story but also joy--and Paris! Definitely recommended.

And here's my description of The Storied Life of AJ Fikry from a few years ago:  Widower AJ Fikry lives above his small bookstore in a tourist town on an island off the Massachusetts coast. He drinks too much, carries only books he likes (he's not a fan of David Foster Wallace), and doesn't really like most of his customers. But then someone leaves a baby in the store and soon he's raising the child, dating a book rep, organizing a book group for police officers, and hosting author events. The book talk/gossip is fun and, although there are sad moments in the book, overall it leaves the reader feeling positive about humanity. Highly recommended.

If you haven't gotten in on the bookshop fad, I suggest starting with these two.