Twenty years ago, I found my mechanic—Victor at Yuki Imports in Los Angeles—via a referral. Since then, I've recommended him to countless friends and colleagues, and I couldn't help but laugh when I saw a sign in his waiting room that asked customers not to write positive reviews on sites such as Yelp. The shop was overbooked with customers, the sign explained, and it couldn't handle the influx of new customers.

That's a nice problem to have. And it might be yours, as well, if you follow some of Victor's best-practices.