Tring Tring !! Hello sir, I am calling from xxxx service center. You had a service few days back, please rate how satisfied you are out of 9 and 10. I am sure you would have heard this kind of survey getting administered.

To do either above or a smaller variation is to muddle with it and paving path to get favorable but misleading results. Below are some of clean implementation of Net Promoter Score.

Popular variations (not recommended) are:
a) Color the nos as per the category – Shades of red, yellow and green for detractors, passives and promoters.

b) Change the scale internally. Include 7 & 8 as promoters since you feel these are also good ratings.

Some best practices:
a) Should be conducted independently and discretely. Should not be influenced by anyone specially when the no of respondents are less and bias could creep in.

b) Should be asked only after the consumer has been able to consume your service and expected some results. If you ask the questions after an interaction where company just registered a complaint is not recommended. The best time is to ask customer after the complaint has been resolved.

c) Customers most preferred mode of communication should be chosen e.g. email / whatsapp etc.

d) Statistical significance is important. A 90% confidence interval with +/- 5% margin of error is acceptable.

Raosoft Sample Calculator

It is important to know what should be sample size for e.g. if you service 20 customers a day. Should this be 20 or 600 (per month) or 7200 (per year) ?

The basic thumb rule is to consider it for your reporting period, the period you review the NPS results.

The next important part of the survey is to ask reasons for being happy or not happy and understanding the relative importance of these factors which i will cover [next].

Barring few of these important guidelines, NPS is easy to administer and get actionable feedback.

Please do comment if the article was helpful to devise your loyalty measurement plan.