McDonald’s in Brazil is giving away 1 million free Cokes. All customers need to do is tweet.

In a first-of-its-kind promotion, McDonald’s has teamed up with Twitter and Coca-Cola to launch the @CocaNoMc program. McDonald’s customers in Brazil simply need to send a tweet to a friend, relative or anyone else whose Twitter handle they know. The tweet must include both @CocaNoMc and an @reply to their friend’s handle. The friend will receive an automated message from Twitter linking to a coupon for a free, 500ml Coca-Cola at any McDonald’s restaurant in the country.

Since the promotion began on January 28, more than 180,000 customers have redeemed their coupons at McDonald’s locations in Brazil, which include the 866 restaurants operated there by Arcos Dorados, the largest McDonald’s franchisee in the world. More than one-third of the 1 million free Cokes have been tweeted to friends. The idea arose from social network conversations between the three companies and their customers discussing the summer, friendships, and ice-cold Coca-Cola.

“Giving away 1 million beverages to McDonald’s customers reflects the growing importance of Twitter and other social media to the people who visit our restaurants in Brazil. The scale of this promotion is exceptional and is only possible with the participation of all three major brands, McDonald ́s, Coca-Cola, and Twitter, working as a team,” says Raúl Mandía, vice president of marketing for Arcos Dorados.

“McDonald’s is an excellent partner for us in this experience, and Twitter is the best platform for supporting such an innovative initiative,” says Marcelo Pascoa, content and connections excellence director for Coca-Cola. He added the @CocaNoMc initiative is the best way to bring the Drink a Coca-Cola with someone concept to life, connecting the digital world with a real consumer experience.

In McDonald’s restaurants in Brazil, soft drink cups are labeled with 21 special designs, including “Drinking a Coke with friends at McDonald’s” and “Drinking a Coke with the family at McDonald’s.”

This is the first time an initiative like this one has taken place on Twitter in Brazil. “@CocaNoMc combines the creativity and innovation of these two important companies with the best of Twitter to really

surprise consumers,” says Cadu Aun, commercial director for Twitter Brasil. “The campaign definitely provides another great opportunity for Twitter users to stay connected with their friends throughout the day and offer them a present in real-time, only on Twitter.”