How effective are offsets as a means to boost a domestic defence industry? This article takes a novel approach to answering this question; examining global data on levels of defence sales over three decades as a measure of successful defence industrialisation (i.e., using the market as an indicator of success). The quantitative data points to a mixed picture as despite the ubiquity of defence offsets, they are no guarantees of success in defence industrialisation. It concludes that offsets can be an important part of a defence industrialisation strategy, but are not in themselves sufficient for success.