eBook formats have yet to be standardized across publisher, eBook retailer or device, but ePUB seems to be growing in popularity. O’Reilly Media has noticed a growth in this format.
Today, Andrew Savikas, VP of Digital Initiatives at O’Reilly Media posted a chart on which eBook formats its customers have downloaded from June 2008 to October 2010. As you can see from the chart above PDF has been the most popular format since the beginning, but ePUB files are growing in popularity.
Here is more from Savikas’ blog post: “At O’Reilly we offer multiple (DRM-free) formats to choose among for customers who buy our ebooks. Since starting the program with PDF, EPUB, and Kindle-compatible Mobipocket formats, we’ve added an Android application file (.apk) and more recently the accessible DAISY format. We track which of the formats customers actually download, and from the start PDF has been the dominant choice, though as the chart below shows, there’s been a steady shift toward other formats, especially the open EPUB format (which can be read on nearly every ereader device, and is the format used by Apple’s iBooks reader).”