It's not enough to just get people in your doors. Once they show up, you have to do a great job of providing an excellent service. And, "churn" (aka monthly turnover) is the secret killer of most fitness businesses. If you aren't able to get a handle on your churn, you can be out of business even if you're adding dozens of clients per month. We talk with Juliet Starrett, one of the wisest and most-seasoned business owners in the CrossFit Game, about how San Francisco CrossFit dials in the client experience at all stages in order to maximize retention.