From Online to Offline: How Brands Use Big Data to Figure Out Where Their Customers Will ShopEcommerce brands are using big data to open stores exactly where their customers want them.

It tookWarby Parkerthree years to figure out exactly how to sate itscustomers' demands. At first, when it launched in 2010, the company was online only: It offered to mail people five different fashion-forward eyewear frames so they could try them on at home, decide what they like and mail the rest back. When sample inventory ran out after two days, customers called the co-founders -- who were then students at Wharton living near campus -- and asked to come to their apartment to try on the product. (They said OK.) Then in 2011, Warby Parker moved into a building in Manhattan, and thousands of people arrived to try on the in-demand glasses. The company's landlord threatened to evict it for monopolizing the elevator.

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