Apple’s iOS 8 and OS X Yosemite, which launched to the public this fall, come with iBooks pre-installed. That decision has paid off: iBooks has averaged one million new customers every week since mid-September.

Keith Moerer, the director of iBooks at Apple, revealed that statistic in a rare public appearance at the Digital Book World conference in New York City on Thursday. It’s startling to anyone who dismisses Apple as an also-ran in the ebook market and might encourage publishers and authors who haven’t focused on the platform to begin doing so. (And that was probably one of the main reasons that Apple agreed to appear at the conference.)

Moerer also spoke about other reasons that iBooks downloads are increasing. Since the launch of the larger-screened iPhone 6 and iPhone 6 Plus, “We are seeing more of our book sales starting to come from the phone.”

Though neither Moerer nor…