T-Mobile Advert "Lifes For Sharing"

This is what i call a genius marketing strategy. It may be a harmless, nonsensical improv stunt, but the commuters were enjoying the happening and some even joined in (later i found out that they did it every 20 mins throughout the day, so ppl who weren't involved could also just be recruited for the next routine). Not only that, curious passerby would be surprised at the commotion and would whip out their camera phone to take pictures and video, hence, viral marketing was born.

Well done T-Mobile!