Hybridbooks, which are print books with bonus digital content. So you can use the code to get a better map, or background information, or what have you. Which I think is a great idea, actually. But it's not a hybrid book. It's not print and digital. It's print, with extra features you can get to online, and that's not exactly new; publishers have provided additional content online for years (book group guides, interviews with the author, often even additional material of just the sort that these Hybridbooks are supposedly newly introducing.)
So I like it in concept, but I think the way it's talked up is silly. It's nothing new, not really. Is this perhaps more or better? Could be. And that's good. But it's not groundbreaking.