No purchase necessary to enter to win. A purchase will not increase your chances of winning. Promotion period is January 1st - March 31st, 2014. Visit www.shazam.net/rules_goforthegold.html for official rules and complete contest details. "Nike" and "Sports Authority" are not affiliated with and do not sponsor or endorse the service of SHAZAM, Inc, or the "GO FOR THE GOLD" campaign.