Trenton, New Jersey, isn't the industrial powerhouse it once was, even if the slogan "Trenton Makes, the World Takes," first installed in 1935, still stands in 10-foot-tall letters across a bridge that spans the Delaware River to Pennsylvania. But a few minutes east of town, inside a warehouse belonging to Amazon, there are signs of another industrial transformation.

Online retailers have raised the bar for convenience and fast delivery - and brick-and-mortar retailers are scrambling to keep up. To speed order fulfillment, they are shipping from stores that are closest to customers. To build on their strengths, they are focusing on the in-store customer experience. And to bring more online shoppers into stores, they are providing Buy Online, Pick Up In-Store (BOPUS) options. At the same time, they are rapidly investing in additional inventory and store labor to stay competitive.