With peak shopping season underway, one business is making it easier for retailers to put deals in customers' hands. The Columbus-based card services division of Alliance Data Systems Corp. has launched the MyLoyalty app, a mobile application aimed at a retailer’s most-rabid shoppers that rolls credit information, loyalty stats and offers into one space. It’s about convenience for customers and boosting sales for retailers, said Sheryl McKenzie, vice president of product and capabilities. “Customers…