Groupon fell following news it’s acquiring CommerceInterface — part of an effort to improve operations at Groupon Inc.’s e-commerce­ business as it seeks to expand globally. No terms were disclosed about the deal, announced Friday. CommerceInterface, of Salt Lake City, provides a Web-based platform designed to help manufacturers, distributors, and retailers­ handle online sales, interact with vendors, and manage operations. Groupon pioneered online daily deals.