When David Cost was hired in 2011 to run stylish teen retailer Deb Shops’ e-commerce operation, he was given one key mission: Fix it. Sales were flat. Your elderly aunt had more Facebook friends and the move to mobile was beginning to heat up in ways that would dramatically change the face of retailing forever. How in the world would Deb Shops turn things around, was the big question. And the answer, says Cost: “We ended up basically just burning to the ground what was here and we rebuilt the business from scratch.” No pressure there, right? But Cost didn’t go it alone. He turned to the tools of the time, harnessing social media help from 8thBridge Inc., machine learning and big data analytics help from BloomReach and a belief that creating a fun and engaging online experience would win the hearts and wallets of the teen girls (and their parents) who buy the prom dresses and hoop earrings that Deb Shops sells. “What’s important is the quality of engagement,” Cost, vice president of e-commerce and digital marketing, says from his office in Philadelphia. “We want people who come to look at and interact with our content as long as possible and consume as much of it as they can.” Now, Facebook followers are up to 2.2 million from 60,000 shortly after Cost arrived. Shoppers whose searches are boosted by BloomReach are staying on the site longer, looking at more pages and spending more money. And Cost is doubling down on BloomReach technology, having just adopted Search, Navigation and Personalization or BloomReach SNAP, the company’s latest product for the desktop and mobile devices. While some retailers are obsessed with tracking the number of shoppers who click through digital ads and land on their sites or focus most of their attention on the rate which visitors convert to buyers, Cost says building visitors into loyal, engaged customers is the way to go. While cautioning that digital merchants can’t let up on making sure that online shoppers become online buyers, professor Kirthi Kalyanam, of Santa Clara University’s Retail Management Institute, says there is no doubt that fostering customer engagement is crucial, too. “It makes sense,” Kalyanam says of engagement efforts, “but only if people have some sensible metrics that are around it and they’re measuring it in those metrics.” I’ll get to Cost’s metrics in a minute. But first, it’s important to understand a basic fact that Cost recognized as he turned Deb Shops’ focus to engagement: Repeat customers are driving sales like never before. A recent Shop.org/Forrester Research survey found that more than half of Web revenue is due to repeat customer spending and that nearly two-thirds of companies surveyed said that repeat customers provided a bigger share of sales in 2013 than they did in 2012. Cost started Deb Shops’ turnaround by adding BloomReach Mobile to Deb Shops' mobile platform. The product supercharges search, navigation and personalization, using natural language processing, machine learning and behavioral patterns to help shoppers find what they're looking for with just a few keystrokes. BloomReach Mobile learns what a consumer is looking for. Rather than typing in a long description, the company’s predictive search will offer complete, relevant search terms once the shopper types in the first two or three letters of a search term. “When we first put this on mobile,” Cost says of the BloomReach technology, “the No. 1 search term was ‘dress.’ Within two days, our No. 1 search term overall was ‘junior graduation dress.’ No one would type that. They were picking it off the list.” The move provided a boon to Deb Shops on several fronts. “For people who interact, who touch a BloomReach feature on mobile, their average time on site and number of pages viewed is three times greater than people who don’t,” says Cost, who adds that revenue per visit is also three times higher for those whose search is enhanced by BloomReach. Overall in the past two years, he adds, Deb Shops e-commerce revenue has increased by a factor of six. And so, Cost is taking it up a notch. Deb Shops was among the first retailers to deploy BloomReach’s latest product: BloomReach SNAP, released this week. BloomReach SNAP provides for the desktop and all devices the experience that had previously been available only on mobile. “In mobile, we saw its impact so quickly,” Cost says. “We didn’t have Mobile up a week or two and we were pushing BloomReach hard for when we could have it on the desktop. If I get similar results (with SNAP), we’re going to rock the house.” Quite a turnaround when you think about it. In just under three years, Cost has gone from burning the house to the ground to seeing the day he’ll be rocking it.