Levi’s have partnered with TBWA to increase exposure to their brand and appeal to Hong Kong youth culture creating ‘Levis Summer Hotline,’ a seemingly innocent bright red telephone booth placed in malls and shopping centers across Hong Kong.

Two popular radio hosts connected with booths via video from the Levi’s store and challenged contestants to answer questions or do crazy stunts. The crazier the stunt, the bigger the prize, which was printed out in the booth like a receipt to be redeemed at nearby Levi’s stores.

The campaign saw nearly half a million people enter the booths over a three day period, and drove sales up by 30%.