On August 12, Authentic Brands Group Inc snapped up Reebok for $2.5 billion, adding the sneakers with the Union Jack emblem to its hodgepodge of brands that includes fast-fashion retailer Forever 21, skateboard specialist Airwalk, outdoor outfitter Eddie Bauer, and shirtmaker Brooks Brothers.

Adidas’s failure to restore Reebok serves as a cautionary tale for any business trying to reignite a brand that’s fallen out of favor with consumers. At the height of its success, Reebok eclipsed even Nike for several years in U.S. sneaker sales, but the boom faded as quickly as it came, no matter how hard Adidas tried to turn back the clock. That task now falls to Authentic Brands, which has made the revival of well-known yet tired brands its specialty.

The challenge for Authentic is whether to simply focus on the Reebok classic styles to create a more profitable niche brand or invest significantly into new styles as well as research and development to try to make a dent in the sales of its former parent and Nike. While Authentic has built its business buying tarnished brands, reviving Reebok may turn out to be a step too far, says Michael Stone, Chairman, Beanstalk