Customer satisfaction score (CSAT) measures how satisfied a customer is with a specific interaction, product, or overall experience. It's typically captured through a post-interaction survey: "How satisfied were you with your experience?" on a 1-5 scale, with results reported as the percentage of respondents who selected 4 (satisfied) or 5 (very satisfied).

CSAT = (Number of satisfied responses / Total responses) x 100

CSAT is the most widely used customer service quality metric, and for good reason — it's simple, intuitive, and directly captures the customer's perspective. However, it has well-known limitations:

• Response bias: Typically only 10-30% of customers respond, and respondents tend to skew toward extremes (very satisfied or very dissatisfied)

• Recency bias: The score reflects the last moment of the interaction, not the overall experience

• Inflated baselines: A CSAT of 85% is often reported as "good," but since only engaged customers respond, the true satisfaction rate across all customers may be significantly lower

CSAT is most valuable when tracked as a trend over time and segmented by channel, topic, agent, or customer segment. A drop in CSAT for a specific issue category signals a systematic problem. A gap in CSAT between human-handled and AI-handled interactions tells you whether AI is meeting customer expectations.

For AI customer service deployments, CSAT is the accountability metric. If AI resolution rates are climbing but CSAT is falling, the AI is closing tickets without actually satisfying customers. The metrics need to move together.

Related terms: Net Promoter Score, customer effort score, resolution rate