Customer Effort Score (CES) is a consumer intelligence metric designed to quantify the ease or difficulty customers experience during specific interactions, such as contacting support, completing a purchase, or onboarding with a product. Unlike satisfaction metrics that capture general sentiment, CES isolates friction at the transactional level, making it a precise diagnostic for identifying where customer journeys break down. Research consistently links low-effort experiences to stronger retention and advocacy, making CES a leading indicator of long-term loyalty. Within qualitative research programs, CES scores gain explanatory power when paired with open-ended conversation, revealing not just how much effort customers reported but why that friction existed and what it cost the relationship.