Over 70% of the developing world gets its medicines from "mom & pop" type kiosks. The problem is that the availability of many medicines is unreliable. mStockGuru is a mobile-phone-mediated inventory control service that asks pharmacists to periodically capture demand & inventory data -- and in return, it sends them text messages when to replenish, and in the optimized economic quantity. The service saves medical stores money on purchasing, and our organization would take only a fraction of the savings in return, rendering the service virtually free to shop owners. More importantly, the mStockGuru service sets appropriate safety stock levels per commodity, thus offsetting uncertainties in both supply and demand, and preventing overstocking. This means predictable and improved availability of medicines to villagers. Specifically, inventory policies will reduce stock-outs, decrease the likelihood of expiry and therefore diminish dispensing of expired medicines to villagers -- all of which preserve community health and improve public health interventions that aim to use traditional pharmaceutical channels. Moreover, because demand data is so valuable for upstream wholesalers, distributors and aid agencies to save money via optimized operations, these data become a powerful bargaining chip for small businesses in the developing world. Kiosks can exchange the data for discounts or cash, empowering them within the supply chain. Since the data can easily be aggregated geographically, store owners can pool risk, ordering bulk quantities or otherwise work together. The idea also works for retail kiosks.