How do you measure the performance of branding marketing?

It is very easy to measure measurable KPIs and prove performance. But same is not possible for a branding exercise. There is essentially no way to measure customer’s feelings about your brand in a quantitative way. Sure you can use surveys to assess what people said before and after a particular campaign but that only works when you are significantly trying to build a new brand story. Essentially every other way is a lot more qualitative. The best in my opinion is to listen to the conversations on the internet. You can use social listening tools to track them.