With the ubiquity of mobile phones—and their inevitable distractions—­jewelers may be tempted to remove them from the sales floor altogether. But savvy retailers and designers know smartphones can work to their advantage when text messages, email, and picture-sharing are used to spark sales. Whether or not your store has a dedicated e-commerce website, real-time communication with existing customers on mobile devices can bring in business that otherwise would not exist.At Christensen & Rafferty in San Mateo, Calif., contacting clients on their mobile phones is commonplace. “Connecting with our existing customers directly can start a conversation that might not have otherwise existed,” says owner Colleen Rafferty. “We take pride in knowing our clients well enough to be able to send them very targeted, very personal selections.”She also sends customers photos directly from