[harshreality]

If that's true why do kindles have native support for other formats or containers like PDF and plain text?

I suppose the idea would have to be that there are significant non-commercial sources of pdf and text documents that someone might want to read on a kindle (think documentation, academic papers, a collection of notes, the kind of things that aren't available through amazon).

However, those same kinds of documents are increasingly distributed as epubs, because PDFs are horrible unless you target one specific output size and resolution (like physical paper), and text simply doesn't offer enough layout flexibility. Epub is the open standard, and anyone who wants layout flexibility uses it. Anything else, including a lot of kindle ebooks, are typically converted from an epub original.

It's not a technical challenge. KF8 is nearly isomorphic to epub.

[bhaak]

> Anything else, including a lot of kindle ebooks, are typically converted from an epub original.

You won't find any epubs in the Amazon Store. That Amazon still allows to side-load other ebooks onto the Kindle is nice but you never known when that hole gets closed up.

It might not be a technical challenge for you but there many people out there for whom it is and those will go to the Amazon Store to get their ebooks there because it's easier to do. And voila, their in the walled garden of Amazon.

PDFs are targetting a different kind of ebooks, those that need to have an exact layout. Amazon is also not really supporting them well, the reading experience of a PDF on a Kindle is awful even though the Kindle DX would have a big enough display for displaying whole pages.

[harshreality]

> You won't find any epubs in the Amazon Store.

I think you misread/misinterpreted. I didn't say there were epubs in the kindle store, but that many of their ebooks were converted from epub format [to get them into the kindle store as kf8 or mobi]. To elaborate: You can't natively edit kf8 or mobi files (at least not with mainstream editors). kf8 and mobi ebooks therefore originate as html or epub (which are pretty much the same thing, ignoring that epubs are zipped, and ignoring simple extras like toc and cover page semantics). Kindle-supported kf8 format is generated using kindlegen operating on either a epub or html source (or some other formats, which aren't recommended because they lack formatting parity with epub/kf8). The point being, ebooks are basically in some quasi-html open format to begin with, Amazon requires converting them to a proprietary format (and kf8 is a very thin proprietary veneer over epub) to get them onto kindles... a conversion that serves no practical, functional purpose.