This paper studies the incentives to undertake uncertain R&D initiatives in a dynamic duopoly network industry. It is shown that network externalities positively affect the incentives to invest in R&D. In the model, competition resembles a preemption race and, therefore, market performance implies an over-investment in R&D in comparison with the social optimum. Moreover, network externalities have an important impact in the dynamic evolution of the industry. Although in the long-run a single firm dominates the market (i.e. wins the race), short-run competition is very fierce and concentrated on neck-and-neck technological configurations. This short-run competition is fiercer and longer, the higher the level of network externalities. Policy measures that increase technological diffusion (i.e. mandatory licensing), increase the level of competition and/or prolong the short-run competition have an important positive impact on consumer welfare and on firms’ R&D incentives.