The daily deals selling model lends itself well to mobile commerce. A consumer may not know where they’re going to be at 11 a.m. every day when Rue La La, for example, posts the products of the day. And because the deals are limited-time and limited-quantity, a consumer will want to get there fast.

This is why Rue La La entered m-commerce—to ensure its customers can get to deals anytime, anywhere. Last year it launched an m-commerce site, m.RueLala.com, and this year it launched iPhone and Android apps. Today the mobile site and apps account for 13% of total sales, and at the rate m-commerce is growing at Rue La La, mobile may account for 20% of total sales next year, reports Stephanie Brocoum, vice president of member marketing.

“We believed early on that we needed to have a strong mobile offering,” Brocoum told attendees at the Mobile Shopping Summit this week in New York. “In the beginning there was a lot of hype, and a lot of pressure from the CEO’s office, and there were a lot of fun and gimmicky apps out there. We understood if we could focus on members’ core needs and develop an app that would be useful, it would create value for them and fill their needs and they would share it virally.”

Sharing was key because to become a member of Rue La La a consumer must be invited by an existing member, who gets a $10 credit for every member she recruits. In addition to offering e-mail invites, Rue La La is using a unique feature of the iPhone to facilitate member recruitment face to face. It has integrated the iPhone’s “bump” technology. When a member with the app open bumps her iPhone into a friend’s iPhone, an invitation is wirelessly sent to the friend’s device.

“What is the core need? We offer real-time competitive selling boutiques and our members have a reason to be at the boutiques when they open,” Brocoum said. “And in addition to shopping, we knew they wanted to share—they earn $10 credits with new members. So we knew if we could connect social and shopping we’d have a winning app.”