To announce its entry into Snapchat in Argentina -- and win some customers over in the process, Burger King created a clever campaign on the platform that leveraged its burgers' own sellling point -- flame grilling.

"Snapking" invited Snapchat users to draw grill marks on images of competitor chains' patties and send them to the BK Argentina account (@BurgerKingArg). Those who played received a free voucher for the real deal.

According to the agency behind the campaign, David Buenos Aires, the campaign apparently got 4.1 million fans of "other" restaurants to participate, and the vouchers, which the agency estimated would be swept up in two weeks, all were claimed within the first 48 hours of the campaign.