Advocate

noun | ˈadvəkət | 1 a person who publicly supports or recommends a particular cause or policy

verb | ˈadvəkeɪt | [with object] publicly recommend or support

A good read on turning users into advocates

Along with useful links and examples of things that work and also discussions of why they work.

A good read for anyone running a business of any kind.

While you’re out reading have a spin through this one as well