McCormack was considered a pioneer in sports marketing. He worked with individual athletes to secure lucrative endorsements including Arnold Palmer, Wayne Gretzky, Monica Seles and Tiger Woods. McCormack also worked with a number of sporting events to develop corporate sponsorships including several PGA tours, Wimbledon, and the Olympics. Long before others, he correctly sensed that corporations would be willing to pay significant sums to be associated with high profile athletes. Over the years, he expanded his representation to models, artists, and other celebrities.