According to the Customer Satisfaction Index of Singapore co-developed by the Institute of Service Excellence at SMU (ISES), the most demanding customers need not be the hardest to please, and they could be the best allies of a business. Citing that managers may impress some but not all customers, SMU Assistant Professor of Marketing (Practice) and ISES Academic Director Marcus Lee explained that the marginal decline in satisfaction is greater when failing to meet expectations than the marginal increase in satisfaction when exceeding expectations. He advocated that businesses seek to meet a baseline service promise for all customers before raising the bar incrementally.