While the ebook has become a familiar concept since 2007 and the launch of the Kindle, there appears to be little consensus over how exactly to spell it. There appear to be three main contenders: e-book, ebook, and eBook.
Unfortunately, it is difficult to trace usage of small orthographic differences to see the popularity of each over time, but there are clear comparisons with the term ’email,’ which started off with the hyphen (e-mail) but is now normally simply spelled email as it has become the standard form of communication over the postal system. In early discussions around ebooks, a hyphen similarly marked the emergent form as alien and distinct from its printed counterpart. Perhaps over time we will drop the hyphen and this ellipsis will demonstrate how the ebook has become embedded within contemporary culture, as it is possible to trace with email.
But this leaves the question of the third orthographic variation, ‘eBook.’ While this may look like a riff on Apple’s branding for the iPod and associated devices, it’s history goes back much further to the first generation of commercial ebook device, and the Rocket eBook in particular. A couple of other devices borrowed the orthography, and it appears to have caught on beyond the brand. Interesting, since the ebook revival in 2006, this orthographic convention has not been widely copied, perhaps due to the dominance of Apple with that kind of orthography. Given its awkwardness, particularly when using the word at the beginning of a sentence, perhaps it should be used only with reference to these historic devices.