Why ePub matters
eBooks are way more than text #
Currently eBooks are a combination of both images and text... except for the Apple iBook reader. iBook borrowed from the draft ePub 3 specification (or was it the ePub standard group who simply adopted Apple's technology?) and allowed for the inclusion of audio and video using HTML5 audio and video embedding technologies. As a result of this early adoption ePub-based ebooks for the iPad, iPhone and iPod touch can view embedded audio and video content directly on the device.
With the ePub standard now being considered a Proposed Specification (See http://idpf.org/epub3_proposed_spec_released For more information) it is time for us to reconsider what we do with our eBook content.
Why go with ePub eBooks? #
With tablet PCs and smart phones becoming ubiquitous the market for ebooks and multimedia content has grown just as fast if not faster. You can now provide a single access point for all your content without having to make it public in the open web.
You can make the book look the way you want to without having to resort to large PDF files (before you mention it I have nothing against PDF; when used properly it's a wonderful and flexible tool, I just happen to think that eBooks are not the right place for PDF content.)
PDF is for the most part a fixed flow layout. You can't really move and re-flow the text to accommodate different resolution and screen sizes. What looks fine on your desktop PC may not look the same in an iPhone without major vertical and horizontal scrolling.
MOBI is popular (Amazon selected it as the format for the Kindle) but, from my perspective it has several drawbacks:
It is a binary format which means that once create the only way to make updates or changes is to edit the original sources and then re-compile into the binary format again.
The format is DRM encumbered.
Encryption locks users to one account and one device.
Large vendors like Amazon.com can remove books already downloaded to devices (See http://www.nytimes.com/2009/07/18/technology/companies/18amazon.html for more information about this incident)
ePub on the other hand remains a text-based format where the files are bundled together in a zip file (easy to generate with any number of modern compression tools) that requires little or no tools depending how familiar you are with generating XML and XHTML content. What's more important is that with ePub 3 you can add multimedia and accessibility elements finally making books as accessible as regular websites.
You can provide your clients with content as engaging as that on your blog or website. The only limitation is that ePub 3 is not widely adopted yet... that is about to change.