Living in the Information Age, we are accustomed to having answers to every question we could possibly have right at our fingertips. However, there are still questions that don’t have definitive answers and these are the ones that tend to drive us a bit crazy. For avid readers like us, one of these haunting questions is a simple one: how many books are in the world?

It’s a deceptively simple question. Sure, you could browse our ISBN database, which boasts a list of over 34 million unique ISBNs, which are used to classify books—but that would not be the correct answer.