Watsonville, Ca. ready mix company Granite Rock uses customer surveys as a sort of "report card" to rate their service and find out what their customers value. They only query certain customers that have done a given amount of business with them and ask them to rate the company along with two other suppliers. Once they have collected this data, they plot it on a four-quadrant graph and analyze the results.
Once the results are plotted and analyzed, they are relayed to the people in the organization that they apply to so changes can be made or habits reinforced.