Subtle approaches for gauging customer service quality include monitoring holding times on incoming call lines, meeting installation/service/appointment times as promised, and number and nature of complaints recorded by call center, service department, and executive intervention. Conversely, the number and nature of commendations received during specific periods is equally as important. In the case of walk-in or drive-in trade, queuing time is monitored. We know that customers' wait time can lead to major dissatisfaction irrespective of the quality of service that's actually delivered once they're needs are addressed/resolved