This paper empirically evaluates the impact of a Government-Initiated Non-Profit Ecommerce Platform (GNEP) on specialty agricultural sales, focusing specifically on Pu’er tea in China. Using a difference-in-differences methodology and a comprehensive panel dataset that covers over 90% of local tea farmers, we uncover a marked substitution effect. The implementation of GNEP leads to an average decline of 11.22% in offline household sales, while online sales see an uptick of 16.88%. Further analysis confirms a universal channel shift from offline to online sales, irrespective of both production levels and tea quality. Contrary to expectations, the overall tea sales volume remains largely stable post-launch. Additionally, premium-quality teas experience a 2.42% price boost online, while regular teas show a 0.40% decrease compared to offline prices. Mechanism analyses further indicate that the increase in online sales is driven primarily by the intensive margin instead of the extensive margin. Although the platform does not significantly expand the number of farmers engaging in online sales, it succeeds in offering a cost-effective avenue for diversifying product offerings and achieving higher prices for premium-quality products. Our study illuminates the transformative role of e-commerce platforms in rural economic development and provides essential insights for policymakers and practitioners.