Net Promoter Score (NPS)

Net Promoter Score (NPS) is a metric used to gauge customer loyalty and satisfaction by asking users how likely they are to recommend a product or service to others. Based on a scale from 0 to 10, users are categorized into promoters, passives, or detractors. NPS is often used to assess overall customer experience and predict future growth.

NPS is valuable because it's a leading indicator of growth — promoters drive organic referrals, detractors drive churn and negative reviews. For SaaS businesses, tracking NPS over time shows whether product improvements are actually improving how users feel, not just whether they're staying. The most important part of NPS isn't the score itself but the qualitative comments — they tell you specifically what's driving promoter behavior and what's creating detractors.

Slack reportedly had an NPS of 60+ in their early growth years — extremely high for a B2B product — which correlated directly with their viral growth. Each promoter was so enthusiastic they became an internal sales force, convincing colleagues and teams to adopt Slack without Slack spending on enterprise sales.