Using Vellum for formatting e-books

Ever since I started going indie and publishing books on my own rather than through a traditional publisher, I have been using Scrivener to create the epub and mobi files required by most retailers. Okay, not ever since — my very first experimental attempts were uploading Word docs to Amazon and Smashwords, and they were resounding failures. But once Scrivener added epub export to its many wonderful writing tools, that is what I have been using as my default e-book formatting program.

I have...