I have an increasingly busy Google Alert for the word “epub”. Mostly, it’s full of PDF-to-epub conversion snake oil. Another popular theme is the gripe that Amazon’s Kindle does not support the epub file format.

Over the last year or two, it’s become increasingly difficult to criticise Amazon for anything about its Kindle ecosystem. Of the big-three DRM-based ecosystems, it still offers the slickest customer experience, and is available on as many platforms and in as many places as Apple and Adobe-based distribution networks (which now includes Google) – more in some respects. There is very little not to like, or at least admire, about Kindle.

So when reporters and bloggers review Kindle or compare it to its competitors, its lack of epub support is a popular topic. Thing is, I think Amazon’s absolutely right to hold off.

I’m a huge fan of the epub format when it’s used and supported well. I’m not a fan of badly engineered epubs and sketchy epub readers. Spotty CSS support is a nightmare for epub producers (especially when working with technically challenged clients). One of the greatest offenders is Adobe Digital Editions and its ARMSDK-based cousins, whose clunky DRM-shackled internals leave them unable to keep up with huge improvements in epub design and device sophistication. (You just can’t get away with an incomplete unicode glyph set, a terrible image-resizer, and incomplete CSS support today like you could in the good old days of 2007.)

What does that have to do with Amazon?

First of all, Amazon doesn’t want those hassles. Amazon doesn’t want a zillion bloggers moaning about how they support epub, when things are simpler just not supporting it at all. Amazon sells lots of ebooks because it’s easy for us to buy them, and their archaic technology means they rarely break. (Incidentally, Apple has tried to dodge similar hassles by limiting epub-CSS support, effectively turning epubs in iBooks into something almost as unsophisticated as mobi.)

Secondly, delivering such basic ebooks to customers makes it much easier to manage their expectations. It’s hard to disappoint a customer when all that customer expects is black-and-white text in one font, and the odd greyscale picture. If Amazon said to its customers, “Now you can open all those big, gorgeous epubs with their embedded fonts, overly complex XHTML and sketchy SVG”, customers wouldn’t know what to expect, and everyone would grumble a lot. In this respect, Amazon’s doing all of us a favour. K.I.S.S.

And third, there’s the market-share strategy. Right now, three separate DRM schemes keep Amazon, Apple and Adobe’s (unwitting) customers walled into their respective gardens. If and when those DRM walls collapse, Amazon still has a file format to keep people coming back to its store. It’s not a strategy I like as a technically minded customer, but unlike many companies before them, Amazon’s probably big enough now to justify pushing its own format for a while.

There’s no doubt that epub is the future of ebook standards. It’s open and has a solid history and an active development community. Its underlying technology is a better fit with web technology generally, allowing more seamless connections between books and websites, apps and databases. (This will only get better with the imminent release of Epub 3.0.) And it has marketing backup from Adobe, Apple and Google. But epub on Kindle? Be careful what you wish for.