Originally Posted by HarryT
Simply the time factor. The LRF and Mobi upload sections have been around a lot longer.
Makes sense. I think the real question is why some of the real 'heavy hitters' in terms of book uploads continue to upload IMP, LRF, PRC, but not EPUB? Especially since LRF was really only ever a Sony specific format and Sony has now abandoned it in favor of EPUB in their store.