It's one thing to write a book, it's an entirely different thing to write one that's a saleable, viable, marketable product. Ensuring the success of a book is something even the biggest publishers have never been able to guarantee. Mitigating circumstances, flash trends, and world events will all affect buyer preferences. That said, there are still ways to leverage the sales-factor in your favor and here's how you do it. 1. Know your readers. We're not just talking about whether your readers .