Hand towel dispensers (e.g., sheet product dispensers or product dispensers) are useful in many environments for providing on demand paper towels for users. Due to their compact nature, it is difficult to provide a large, long standing supply of paper towels. Thus, janitors or other maintenance personnel (e.g., maintainers) are often required to replace empty paper towels. The variable nature of use, however, makes it difficult for a maintainer to predict when a replacement will be needed. Moreover, schedule demands of a maintainer and the desire to avoid wasting paper left on a roll leads to the situation where the maintainer may be unsure whether or not to replace a towel roll. In this regard, the situation of having no paper towels in the dispenser (a completely empty scenario) may arise.