Choice is great, but at times it can also be overwhelming. Wine.com's customers, who are not oenology experts, felt confused when they went to the site to buy wine. With such a wide selection of vineyards and varietals, they sometimes found the process of choosing a bottle unwieldy.

To further compound matters, about half of the wine retailer's customers buy gifts when they visit the site, says Cam Fortin, Wine.com's director of business development. This statistic added pressure on the company to help customers make the right choice.

With thousands of bottles to choose from, even wine connoisseurs sometimes find it difficult to find what they want, Fortin explains. Wine.com wanted to make it easier for its customers—whether amateurs or experts—to find the best bottle of wine for their needs. The company's leadership recognized the need to introduce recommendations that are personalized to the individual customer based on his browsing and purchasing history and taking into account searches and purchases made by customers who are considered similar to them.