Currently, about 20% of Wal-Mart's e-commerce business goes through the aforementioned 83 Supercenters. Second, ship-from-store opens the inventory of stores to the e-commerce channel. Best Buy, for example, accelerated its online sales growth in part by reducing the number of instances in which items were out of stock online. When an item is out of stock at Wal-Mart or Target's online distribution centers, there's a good chance it is sitting on a shelf at a store location somewhere near the customer. As Wal-Mart and Target expand their ship-from-store programs, the primary challenge will be logistical -- keeping track of inventory across the various channels and routing online orders to the most appropriate location. But the payoff could be significant, with fewer online customers abandoning their orders due to unavailable items. Lastly, ship-from-store has the potential to greatly reduce shipping times.