It used to be the old boy network. Powerful businessmen would take care of their own, finding good jobs for anyone who managed to graduate from the right school or move in the right circles.Nowadays, it's just as likely to be small business owners -- with nothing to tie them together except being business owners in the same community -- who take care of their own. They may offer advice to one another, help each other successfully bid on projects, provide cross referrals, and otherwise help make each other successful. Sometimes the way they help each other defies an exact description, as noted in this article by Amy Wu in the Democrat and Chronicle. I'm quoted in the article saying there's not an exact description for it. But if it is working for the business owners, who needs exact descriptions anyway?