In a limited form cellular providers have long shared capacity in the form of roaming agreements. As devices and infrastructure become more agile, such sharing could be done on a much faster time-scale to enable one provider to acquire “overflow” capacity from another provider, based on time-varying demand. This may provide carriers with an attractive means to better meet their rapidly increasing bandwidth demands. On the other hand, the presence of such a sharing agreement could encourage providers to under-invest in their networks, resulting in poorer performance. We adapt the newsvendor model from the operations management literature to model such a situation and to gain insight into these trade-offs.