Case studies and basin reviews are presented which underscore the critical role that new E&P technology has played on tight gas resources, transforming subeconomic prospects into 'hot' plays. This report, the last of a four-part series assessing unconventional gas development in the US, examines the state of the tight gas sands industry following the expiration of the qualification period for the Sec. 29 Nonconventional Fuels Tax Credit. This article discusses how rediscovered tight gas plays and the evolution and extraction technology have shifted the outlook for tight gas drilling and its economics from a low productivity, marginally economic resource to a low-cost source of gas supply.