Last year, Publicis Groupe took full advantage of YouTube's annotation feature with an interactive greeting card featuring Maurice Levy. This year, it works with agency DigitasLBi for another tech feat -- this time, the video recognizes how many people are watching the video with you.

Since Publicis' own family is about to grow, with the merger bearing down upon us, the theme this year is "The More, the Merrier." So two people releases confetti, while more brings gospel singers, cheerleaders, Chinese dragons and more. The video uses your webcam and facial recognition to count how many people are watching the video together.