The problem with most attempts to get customer feedback is that they want too much of their customers time. Your customers are busy and they don't want to spend even a few minutes answering questions. 

This hesitation also applies to options. 

Ask someone to rate you out of 10 and immediately the confusion starts; "Are they a 6 or 7? What's the difference?" This causes them to doubt themselves and eventually the majority of people will not give an answer.

Even then you won't agree on them as to what 6 or 7 mean.

So you need to reduce the options. Some people do think a 5-point rating scale works but again it causes people to hesitate. While the number of people who don't respond will be reduced, you won't get the maximum.

A 3-point, word-based system solves this.

People immediately rule out one extreme and then just have to decide whether between two options. For instance someone who is happy will automatically rule out "Terrible" as an option. All they have to do is decide if they are Happy or Very Happy. 

So you get more people responding and because they don't have to think about it you get their true feeling.