Or say the author of this article claims. A lot of what they say is sound advice for good writing, but some of it is a tad pedantic (i.e. they perpetuate the "split infinitive" thing that gets my goat so much). Also, I don't really think doing as they suggest is going to get you a bestseller. I mean, basically, their advice is "Write well!" Yeah, that's nice and all, but a lot of bestselling authors don't "write well" as defined by the article and I'm sure there are a lot of technically virtuous manuscripts out there no one wants to read. Being a bestseller is, I've come to believe, really about luck and marketing and sheer chance, not whether you use active or passive voice.