Fruit and vegetable vendors in Bogota travel most days to a central market to purchase produce, incurring substantial costs. A social enterprise attempted to shorten the supply chain between farmers and vendors by aggregating orders from many small stores and delivering orders directly. We randomized the introduction of this service at the market-block level. Initial interest was high, and the service reduced travel time and costs, and increased work-life balance. Purchase costs fell 6 to 8 percent, there was incomplete pass-through into lower prices for consumers, and markups rose. However, stores reduced sales of products not offered by this new service, and their total sales and profits appear to have fallen in the short-run, with service usage falling over time. The results offer a window into the nature of competition among small retailers, and point to the challenges in achieving economies of scale when disrupting centralized markets for multi-product firms.