Steve Campitelli wrote:
Is there any time during a file update that a book file is unavailable? I.e. when I upload an updated mobi to bookshelf, is there any period where the file is not available to buyers?
No, not unless you have unplublished at some point (which you don't need to do). It should just flip from the original to the updated version when Amazon flick the switch. They'll email you (usually) to let you know when that is.
The above said, there really does appear to be a drop off in sales for a day or two after I make updates. The book is available, but how it shows up in search results and Amazon's algorithm for exposure may be disrupted until the system works out where your book should be with whatever changes you've made.