The Kindle e-reader client for Windows 8 does not support loading user-created MOBI format content. Writer Patricia “Pooks” Burroughs discovered this recently, and when she contacted Amazon to inquire about it she received an email from Amazon support saying simply that Kindle for Windows 8 did not support user-generated content at this time and they are “really sorry about it.” She subsequently posted an open letter to her blog blasting Amazon for removing this ability.
In terms of breaking news, this is pretty much a non-story. The sky is not suddenly falling. All indications are that the issue is as actually old as the first version of the Kindle Reader available for 8, months ago, and Burroughs only noticed it today. (She was under the impression an older version of the Kindle Reader for Windows 8 could read MOBI, and Amazon just removed it in version 2.0 released a couple of weeks ago. However, reviews from as far back as January and Amazon support threads from November complain about this missing ability. It is possible that when her friends got their Windows 8 tablets they might have had the old Windows 7 client loaded on them, which did and still does read MOBI files.)
Still, neither I nor Nate Hoffelder was aware of this lack of support for user-generated content when we first heard about it today, and I think it does bring up some points worth discussing. A lot of people do buy or make their own non-Amazon MOBI content. They might buy books from Baen, or download a MOBI file of news stories from InstaPaper or some other aggregator. They might just want to put word processor files on it for later review. If they’re thinking about getting a Windows 8 tablet or desktop, they should know ahead of time the reader isn’t going to work, and they’ll need to find alternative methods of reading MOBI files (of which there are indeed several) until and unless Amazon adds user-created file support.
But just because Windows 8’s Kindle app does not currently read user-generated content does not mean it always won’t. When the Kindle app for iOS first came out, you either had to jailbreak or use the “iPhone Explorer” desktop app to sideload content into it, because there was no “legit” way to install it. (This was especially irritating given that Amazon had bought MobiPocket and killed off the official iOS Mobi app that had been under development.) But a few months later, the Kindle app got the ability to read user-generated content after all, including opening it from email or web links as well as loading it with iTunes app sync.
It seems unlikely Amazon intends to block user content on the new main version of Windows for very long. Even apart from all the added scrutiny the company has been getting since the whole agency pricing thing kicked off, if Amazon intended to change its policy on user content it would remove it from all the other platforms as well, and that certainly has not happened.
What I find most probable is that, in the expansion to a new platform, just as with the iOS app, Amazon is developing the core functionality of reading its own books first. Some of those past reviews indicated early versions were extremely buggy, and it makes sense to kill the bugs—and make sure Amazon gets its own stuff right first—before adding new features. I wouldn’t expect support for user-generated content to be absent for very long.