Jake,
I can assure you that I don't, haven't and won't be working for epubbud. (You can see more about me and the book at carpeaudience.com) My first experience with epubbud was in purchasing an ISBN number last week that was accepted by Apple. Since it was formatted in iBook Author the only place that eBook appears is on Apple's bookstore (Per contract.)
Recognize that distributing through Apple carries a 30% "Commission" going to Apple on every sale. My take is that is a fair price for the store exposure, digital delivery, reporting and payment processing.
I found a free eBook from O'Reilly Media called "Publishing with iBooks Author" that answered some of my questions. It may still be free at oreilly.com. But your first step is to create an account and decide if you want to abide by the Apple contracts. That can be all done online.
Managing books looks pretty cool. There's a simple dashboard that allows you to control your pricing and distribution. And provides you with feedback during the acceptance process. You'll also need to get iTunes Producer and Application Loader for uploading your books to the Apple store.
All that said, I'm still brand new to the process. Having heard that it takes weeks to go through the acceptance process, I was delighted that it only took a weekend. Wow. Seeing the software and reporting options that are available for iTunes Connect was also exciting. (And an iPad app for iTunes Connect). Getting Promo Codes so I can get promotional copies out is cool too. So it really is with wide-eyed wonder that I am walking down this path.
PS: One more thing on ISBN numbers. It really feels like domain names. You can spend hundreds to register a domain or you can do it for under $10. I was willing to risk a low cost ISBN and it was accepted by Apple. If it proves problematic, I can change.
Good luck.