I have a friend that writes porn using open source tools. Her stuff is on AMazon as well. She also told me how their numbers work. A book at this author's rank sells maybe 1 book a month. That's not good. Anyway...she uses openoffice to write her docs, then uploads to kindle. She authored some kinky shit like Control - A Billionaire Romance series that got high sales and turned on lots of folks. If you're into that sort of thing, like bondage and such.