In an attempt to help someone on the KindleBoards.com forums make it so that they could have e-books be directly downloaded onto a Kindle via its integral web browser, I have learned that the Kindle — at least the latest generation — is rather picky about what it will allow. In a nutshell, it must be a “.azw”, “.prc”, “.mobi”, or “.txt” file; and the web server must send an appropriate Content-Type HTTP response header. Also, the link to the book must not target a new tab/window, i.e. you must not use a “target=’_blank’” or similar target attribute in your HTML <a> tag.
The content-type (a.k.a. “MIME type”) info was discussed in a thread at the MobileRead.com forums, where they pointed out the need to use “application/x-mobipocket-ebook” as the value for a MOBI file. Without getting too geeky (hopefully), this is information that the web server sends in “headers” that you don’t normally see in the results when, for example, you request a web page on your browser; but the browser does see it, and uses it to help it decide what to do with the actual content that it then receives after those various HTTP headers. I am not going to try to teach you how to configure web servers here, but just to be aware that if you want to post e-book contents on a web site and desire that a visitor be able to download it while browsing there on his/her Kindle, then you need to supply the correct content-type header, or else the Kindle will reject it and refuse to download it. The MobileRead forum thread suggests that you can also use the more generic “application/octet-stream” Content-Type header, but I have not tried that so cannot personally vouch for it, but it sounds reasonably plausible.
Also, as mentioned above, because the Kindle’s web browser does not support tabs or separate windows, it will not support HTML link tags that try to target one. So when creating your web page link to your e-book, do not use a “target” attribute:
<!-- this will not work --> <a href='the_greatest_ebook_ever.mobi' target='_blank'>Read My Book</a> <!-- this is OK --> <a href='the_second_best_book_ever.mobi'>Read This Book</a>
Hopefully that may help someone who is having trouble getting their book to be downloadable by a Kindle and not understanding why he/she is getting those irritating error messages.
