What is a customer satisfaction score (CSAT)?
A customer satisfaction score indicates how satisfied your current customers are with your product or service.
Why should you measure your customer satisfaction score?
This metric shows how happy your customers were with the whole process: from finding out how to contact you, the actual conversations and also any follow up correspondence you might have sent.
It also helps identify pain points in order to see which aspects of your support could be improved.
You can get an indication of the quality of replies, too. You can use this information to identify what aspect of your support you can improve.
Learn everything you need to know about customer service metrics: http://blog.kayako.com/customer-support-metrics/