To understand what led to WAAT convincing the Federal Radio Commission (FRC) to maintain its license, we can look at several key factors and arguments that may have played a role in the decision.

1. Community Support: WAAT likely demonstrated significant community support, showing that it served an important role in the local area. This could include letters from listeners, local businesses, and community leaders expressing the importance of the station.

2. Regulatory Compliance: The station may have provided evidence of compliance with FRC regulations, including programming standards, operational procedures, and financial transparency. A solid track record in these areas would help bolster their case.

3. Programming Value: WAAT might have showcased its unique programming that contributes positively to the community, such as local news, education, arts, or cultural programming that isn't available elsewhere.

4. Mitigation of Past Issues: If WAAT had faced issues in the past that led to scrutiny, they may have presented a plan for improvement. This could include changes in management, programming, or operational practices to address any previous deficiencies.

5. Advocacy from Industry Peers: Support from other broadcasters or industry organizations could have also influenced the FRC's decision, with peers advocating for WAAT’s value in the broadcasting landscape.

For a detailed examination of the case, including specific arguments and outcomes, one would typically refer to the FRC's decision documents or relevant broadcasting history sources. If you need more specific information or case studies, please provide additional context or details.