|
The EPub format is most common.
Amazon is using a Mobi format for their DRM. To the best of my knowledge, Amazon is the only one using Mobi.
That said, if you are willing to strip DRM's or convert formats using Calibre, or a similar program, the format should not restrict you.
Amazon has the largest bookstore in the US. I believe that Amazon has one of the largest bookstores outside of the US as well.
|