I'm surprised there aren't more contributions to the business genre portion of the WEbook site. As authors, it's likely that time is filled up by writing your own books and blogs, speaking, etc., and maybe non-fiction demands more direct payoff over fiction? However, take a look around the site, and you'll start to sense the community there. Readers chime in and offer thoughtful feedback to writing, and writer ratings get boosted. If not just for self promotion, there's certainly some personal benefits to contributing or starting your own project there.
If anyone has taken part in this, post a comment. It would be great to hear about the experience.