In urban American telephone conversations, we propose, the final exchange of goodbyes doesn't terminate the conversation per se but brings to completion a process of leave-taking in which the two parties reaffirm their acquaintance before breaking contact. This process is optional, so that if the two parties are not acquainted, they should omit the process and not exchange goodbyes. We tested this proposal by examining goodbyes offered to operators in routine inquiries to a university switchboard. In requests for a single number, callers offered goodbye only 39 percent of the time. This percentage increased, however, (1) when callers asked for more personally revealing information, (2) when callers felt more appreciation for the information they received, as indicated by their use of thank you very much instead of thank you, and (3) when operators revealed more about themselves by making and then correcting their own mistakes. These and other findings suggest that the more closely acquainted the caller and operator feel they have become, the more likely the caller is to want to reaffirm acquaintance and say goodbye.