The University of North Dakota (UND) Libraries have developed a multi-award winning Customer Service Program (CSP) involving longitudinal assessment and continuous improvement. The CSP consists of iterative training modules; constant reinforcement of Customer Service Principles with multiple communication strategies and tools, and incentives that boost morale and foster not only compliance, but initiative-taking and innovation. The CSP became a widely adopted part of campus-wide assessment, beyond the libraries. Subsequent presentations at conferences led to multiple requests and implementation at other libraries.