Summary: Aug. 31 (Bloomberg) -- Alex Chang, vice president at American Express Sports Entertainment, says digitization and creation of mobile phone applications are key to enhancing onsite sponsorships at events, such as the U.S. Open. Chang talked to Bloomberg's Kathleen Hays and Vonnie Quinn on "The Hays Advantage" live from the U.S. Open on Bloomberg Radio on August 30, 2012. (Source: Bloomberg)
