While e-book sales have exploded in the last year, sales of print books have suffered, hitting brick-and-mortar stores especially hard. But the independent bookstores that have survived the growth of Amazon and the big bookstore chains have tried to retool over the years to become tougher, more agile and more creative in finding new sources of revenue beyond print books.

Anne Holman, the general manager of The King’s English Bookshop, an independent store in Salt Lake City, said an industrywide discussion began a few years ago about whether to charge for events.

“We don’t like to have events where people can’t come for free,” Ms. Holman said. “But we also can’t host big free events that cost us a lot money and everyone is buying books everywhere else.”

The bookshop now requires book purchases or sells tickets for around half of its 150 annual events, up from 10 percent five years ago.

Heather Gain, the marketing manager of the Harvard Book Store in Cambridge, Mass., said that in recent years the store had begun doing more events that required the customer to buy a book, constantly reminding them that “if they aren’t purchasing the books from the establishments that are running these events, the bookstores are going to go away.”

“We’re a business,” Ms. Gain said. “We’re not just an Amazon showroom.”

Roxanne Coady, the owner of R. J. Julia in Madison, Conn., was one of the first prominent booksellers to begin charging for events about five years ago, a move that she considered “desperate” at the time. A ticket to get in, she said, generally can be paid toward the price of a book.

“We were so nervous about it,” she said. “What we’re saying to our best customers is, if you’re shopping with us, nothing’s changed. But for those folks who consider us cheap entertainment, then this is a good way to talk to them about the fact that the way to show your appreciation to the author and the bookstore is to buy their book.”