The title What Makes A Book Sell? at Jill Corcoran Books sounds as if the post is going to be all about marketing. It's not.
Scroll down to the numbered items. "Brainstorm concepts and pitches before you commit to a new book." Again, because that line includes the word "pitch" it sounds as if we're talking sell, sell, sell here. However, I read an article in a SCBWI Bulletin recently that suggested doing the same thing before getting started on a new writing project. Being able to concisely describe your idea--to yourself--helps you to define what you're going to do. I wonder if it wouldn't be a helpful technique for an organic writer in terms of getting a plot started.
Also, this post included another interesting line: "Almost no one expects musicians to get good on an instrument without years of lessons, books, years of practice. There is a similar learning curve for writing." How many new writers realize that? How many people who want to become writers realize that? I certainly didn't back years and years ago. I thought every para I wrote was brilliant and publishable. Thank God others didn't.