2005 Q3 Net Promoter Index
In a previous newsletter we discussed a relatively new customer satisfaction indicator that has a very high correlation to the growth prospects for a company. Based on research that was reported in the Harvard Business Review, the Net Promoter Index (NPI) is based on the percentage of customers that are extremely likely to recommend a company to others. A high NPI bodes well for the growth of a company while a low NPI has the opposite implications.
SPG has been incorporating the NPI in most of its customer surveys that it has completed during the past year. Although it is too early for us to assess the correlation of high NPI to company growth the initial results in our database indicate that a high NPI is indicative of company growth.
The accompanying chart illustrates the range of NPI’s in SPG’s database to date. As noted below, the lowest score in our database is -14.3 while the highest score is 78.6. Note the average score of 31.1.
The maximum attainable NPI is 100 and the lowest NPI is -100. SPG has created a rating scale to interpret the scores.
| NPI Rating | SPG’s Interpretation | |
| 100 | Perfect | |
| 85 to 99 | Spectacular | |
| 70 to 84 | Excellent | |
| 55 to 69 | Very Good | |
| 40 to 54 | Good | |
| 25 to 39 | Average | |
| 0 to 24 | Mediocre | |
| -25 to -1 | Poor | |
| -50 to -26 | Terrible | |
| -100 to -51 | Abysmal |
Although the NPI can be used as a standalone indicator, we recommend that it be used in conjunction with the Customer Satisfaction Index (CSI). The CSI is broader in scope and can closely pinpoint areas of concern to customers.