Generating sustainable business value from information services is challenging on the web where free information and zero-switching costs are the norm. This study examines the role of free comments given in a commercial information service through the lens of the expectation-confirmation theory and continuance. Data from a question and answer web site are analyzed by structural equations modeling to test the theoretical model whereby customer satisfaction is key to continuance and is predicted largely by social interaction that takes place on the site. The model is supported by the field data retrieved from the site. The data show that people came with equal expectations, received equal service, and continued to use the system if they were satisfied with it. Satisfaction was predicted by conversation. Free activity emerges as an integral part of the service in a fee-based information market, improving satisfaction and continuance, and thereby leading to measurable outcomes for the commercial owners of the site. The findings, based on unobtrusive field data rather than self-report questionnaires, extend expectation confirmation theory by adding a social dimension to it.