Steve Chiotakis: The publishing industry’s biggest trade fair kicks off today. The BookExpo has been around for more than a century. But the number of people going is slipping.

So Marketplace’s Jennifer Collins says this year’s event is getting a boost from players who aren’t exactly in publishing.

Jennifer Collins: For the first time, Apple is meeting with publishers at BookExpo America. Why? It’s the iPad.

Al Greco: They sold more in nine months, more units in nine months than Amazon did in three years.

Fordham University professor Al Greco says Amazon’s Kindle still rules in e-book sales. But the iPad has quickly captured 10 percent of that market.

Greco: They are a player in the book publishing industry today. And my guess is they think they’re going to become a bigger player down the line.

He says so will lots of other tablets and e-book readers. Oren Teicher of the American Booksellers Association says to survive, retailers need to know how to operate in the digital marketplace.

Oren Teicher: We know that some of our customers some of the time are going to want to read books digitally and we’re going to want to provide them to them and that’s what we’re trying to do.

Teicher says 300 of his members — independently owned bookstores — are now selling e-books through a digital partnership with Google.

I’m Jennifer Collins for Marketplace.