The best and worst teachers become well-known to the parents. I think an eye-opening tool for administrators would be to survey the parents to pick their child's teacher(s). It would become clear who was doing their job effectively, amazingly, and abhorrently.

Physicians, therapists, coaches, dentists, et al create successful businesses through their reputation of quality work . I am compelled to serve my client (ie: customer) to the best of my ability because A - it's my job AND B - it's my future jobs.