This paper presents an empirical study of the shareware industry, an industry in which computer software is distributed under a voluntary payment system. Although the reasons why people might pay for such a public good are addressed, the paper's primary objective is to reveal for instance, how many people actually do pay. The data used in the study was compiled from a written survey of shaieware authors and summary statistics on numbers of registrations, development hours, distribution times, and prices are presented as are estimatcs of rates of return. The overriding finding is that the distributions of registrations and rates of return are highly upward skewed. However, entry into the industry can still be rational, as the expected return may very well be positive. Furthermore, variable costs are negligible and for many authors, the opportunity cost of programming is zero.