The document discusses Net Promoter Scores (NPS), which measure customer loyalty and likelihood to recommend a product or service. NPS is calculated by subtracting the percentage of detractors (ratings 0-6) from the percentage of promoters (ratings 9-10). While simple, NPS has limitations such as reducing an 11-point scale to 3 points. The document provides tips for using NPS effectively, such as collecting additional feedback to identify root causes, comparing to industry benchmarks, asking detractors for explanations, and focusing on ease of use to improve scores.