It was nearly impossible to escape this week without stumbling upon a tweet or Facebook status update about The Old Spice Guy (aka Isaiah Mustafa). If you haven’t checked out the YouTube response videos, you’re missing out on one brilliantly executed social media campaign.

Social media practitioners constantly talk of the need for “engagement.” Everyone claims to be doing it; few actually do it. It’s safe to say, the Old Spice’s marketing agency, Wieden + Kennedy gets it. What makes this campaign truly remarkable, is how quickly the writers and producers of the videos responded to real-time questions and comments sent to them via Twitter, Facebook and YouTube. For instance, one Twitter fan asked the Old Spice Guy to propose to his girlfriend. The request was sent at 7:06pm ET on July 13th. The response came in at 8:29pm:

There were 87 180 such videos in a two-day span – all of them custom responses to specific questions.

You can’t get any more engaging than that. For the recipient, they get a video they can’t help but share with their followers, helping to catapult the campaign to viral heights. According to Iain Tait of Weiden, what made this campaign so successful was how closely social media specialists worked with the technical team.

“We’re looking at who’s written those comments, what their influence is and what comments have the most potential for helping us create new content. The social media guys and script writers are collaborating to make that call in real time. We have people shooting and we’re editing it as it happens. Then the social media guys are looking at how to get that back out around the web…in real time.”

Trust also played an important role – Proctor and Gamble left it to Weiden to wage this campaign with little supervision. Speed kills in this business, and Proctor and Gamble were smart to let their pros do their jobs.

For a walk down memory lane, here’s the original TV commercial that started it all: