Both methods have their benefits. Single metric is easier to set up and measure, but is more difficult to apply than a composite score. The choice of which to use depends on the size of your business, the complexity of your service and the investment you want to make in measuring satisfaction. Ysatisfy can help you in making the right choice.
The key to success in any customer satisfaction programme is to make sure it's part of a bigger customer focus strategy. If you don't, then it's likely the program will fail. Find out more in Customer focus.