The best way to celebrate your birthday is to throw a party for your loyal friends, and Diet Coke has used this approach in its recent ‘surprise’ promotion in NYC. The beverage brand, which is celebrating its 30th anniversary this year, arranged 30-second long parties for winners of its Twitter competition.

The brand launched a competition on @DietCokeUS, asking consumers to share the joy and complete simple tasks such as composing a haiku, finishing a sentence, or sending a birthday wish using the #DietCokeBday. The winners of the competition, which was running for just a few days, from July 29 to August 1 (30 days would be much better), received a loud surprise—a super short, action-packed parties plus a certificate for a year’s supply of Diet Coke.

The footage can be watched on the official channel of the brand on YouTube (there were four parties for each of the winners).