At 8:48 p.m. Sunday night, Oreo tweeted this ad with the caption "Power out? No problem." Since then, it's been retweeted more than 14,000 times (and the same image on Facebook has gotten more than 20,000 likes) — meaning that the most powerful bit of marketing during the advertising industry's most expensive day may have been free. Twitter has been collectively wondering who deserves a raise.

The answer: The agency behind the on-the-fly ad was 360i.

"We had a mission control set up at our office with the brand and 360i, and when the blackout happened, the team looked at it as an opportunity," agency president Sarah Hofstetter told BuzzFeed. "Because the brand team was there, it was easy to get approvals and get it up in minutes."

Oreo had already aired a solid TV ad with their "Cookie or Creme" spot. But they were ready to capitalize on social media as well when the lights went out.

"The big question is, what happens when everything changes, when you go off script?" Hofstetter said. "That was where it got fun."

The key? Having Oreo executives in the room, ready to pull the trigger.

"You need a brave brand to approve content that quickly. When all of the stakeholders come together so quickly, you've got magic," Hofstetter said.