Katherine Barchetti, a well-known upscale retailer said, "make a customer, not a sale." Why? Because a loyal customer provides substantially more value to your company than a one-off sale ever could. Every time a customer comes back to make a repeat purchase, they're driving up their customer lifetime value with no additional acquisition costs-but effective upselling and cross-selling in retail can be challenging without data. Here's how to upsell to first-time buyers to convert the second sale.