Abstract No firm can last forever on its existing products. It is necessary for a firm to invest for the future through either entirely new products or enhancements of existing products/services. Thus, investments on innovations constitute a major proportion of firms' total investments. To manage their investments in innovation, firms track the success and progress of their innovations. There is a growing body of research on ?innovation metrics? ? the measures used to track innovation progress. We review the state of the art on innovation metrics, report on the usage of metrics by firms, and highlight the measures that have proven to be most useful to firms.