In this study guests of casual-dining restaurants were asked to report how they preferred to complain about service failures they experienced while dining. Guests who reported higher levels of frustration, a higher propensity to complain, and greater information inadequacy generally preferred to complain face-to face to a manager or via a letter written to management. This finding diverges from the expectations created by communication theory, which suggests that face- to-face communication is "richer" than written approaches. Moreover, this study found that complaints lodged face-to-face to nonmanagerial service employees were viewed similarly to complaining via a comment card-a less-rich mode of communication.
Susskind, A. M. (2006). An examination of guest complaints and complaint communication channels: The medium does matter! [Electronic article]. Cornell Hospitality Report, 6(14), 6-12.