At UsabilityOne we have become aware of the increasing interest in using the Net Promoter Score (NPS)® in user research projects, as a way of measuring the likelihood that customers will freely promote their product or service through word of mouth. The NPS was designed (by Fred Reichheld in 2003) to obtain an indication of customer loyalty to a product or service. Reichheld and his team were interested in finding out how the customer experience affected company growth. Their study found that participants’ scores for one particular question – their likelihood to recommend – correlated strongly with customer behaviour (repurchases, referrals and other actions that contribute to a company’s growth) for most mature, competitive industries.
When the NPS is applied to user experience research, participants are presented with a single item questionnaire at the conclusion of a user testing session: “On a scale of zero to 10, how likely are you to recommend [this product] to a friend or colleague?”
On this scale of 0 – 10, participants are classified as:
0 – 6 = “Detractors”
7 – 8 = “Passives”
9 – 10 = “Promoters”
The final NPS is calculated by subtracting the percentage of “detractors” from the percentage of participants that are labelled “promoters”. A positive NPS (>0) is generally considered as good. The idea being that a positive score indicates the product or service is good enough to generate positive word-of-mouth and therefore generate sales and growth.
Disadvantages of using the NPS in user experience research include that, in the event of a negative NPS calculation, it does not provide any indication of the issues or fixes required to improve the product or service under development. In addition, some statisticians claim that there is limited scientific evidence to show that the NPS is a better predictor of growth, when compared to other customer satisfaction questionnaires, and that information could be lost when the 11 point scale is collapsed to three components during the process of score calculation.
Advantages of using the NPS in research include that it is simple and intuitive to administer, easy to calculate, and provides quick insight into whether or not customers are likely to promote the product or service being developed and tested, upon launch. It has also been suggested that the NPS can motivate an organisation to become more focused on improving its customer service and products, and also been claimed to correlate with company revenue growth.
With many proponents and detractors, there is a clear need to further investigate the relationship between the NPS and other measures of usability, to assess its relevance to user experience research of digital products.