In 1942, the first ratings index for radio listeners were created. These rating systems are the beginning of an audience measurement system.

Today, Service Designers use similar rating systems to rate the experience of users when they use a service to find out what needs to be improved in a customer journey. More on that when we talk about the Net Promoter Score, or NPS, in a few pages.

This article is part of the book "A Tiny History of Service Design, " a tiny two-hour read that goes through the historical events that created what Service Design is today.