Have a "Golden Ticket" style give-away à la Willy Wonka. Have between 5-10 "Silver Cards" or something along those lines that can be redeemed for prizes. Prizes could include tickets to sports games, trips to visit the team facilities of various sports franchises, or allow the winner the opportunity to have a sports card made of themselves! They could pick their sport, the stats, the bio, and that card could be distributed among the regular cards from the company.