Samsung bought five-and-a-half minutes of airtime on the Oscars -- a hefty expense to win attention on one of the country's premiere advertising events. Yet what got everyone buzzing the next day wasn't one of its lavishly produced commercials, but a single photo on Twittter.

When host Ellen DeGeneres whipped out a white Galaxy Note 3 in front of 43 million viewers to take a selfie of the star-studded front row at the event, Samsung struck its own Oscar gold. With more than 3 million retweets within two days, the snapshot is pretty much assured a position in social marketing history next to Oreo's blackout tweet during the 2013 Super Bowl.

Samsung isn't discussing exactly how the picture came to be. But the marketer spent an estimated $20 million on the broadcast, which likely included its sponsorship deal with ABC as the official behind-the-scenes sponsor. It also inked a Twitter deal for promoted celebrity selfies from the greenroom backstage. Its creative agency is 72andSunny and media shop Starcom Mediavest.

Samsung claims the picture was unplanned. "While we were a sponsor of the Oscars and had an integration with ABC, we were delighted to see Ellen organically incorporate the device into the selfie moment that had everyone talking. A great surprise for everyone, she captured something that nobody expected," the company said in a statement.

But the selfie seen 'round the world was surely not just serendipity. "It was absolutely no fluke," said Josh Feldmeth, CEO of Interbrand New York, Toronto, and San Francisco. "The conditions were perfectly cultivated for that to occur … it was not by chance."

Social-media tracking company Kontera, in fact, found that not only did the picture get attention on its own, but that it also raised interest among viewers for Samsung's commercials, themed "One Samsung." Kontera dubbed Samsung the brand winner of the night, saying it got 40,000 brand mentions during the Oscars for the seflie, which caused attention to its commercials during the broadcast to spike upward. "I don't think the spikes would have been that high without that moment," said Ammeil Kamon, exec VP-product and marketing.

While no one would put an actual price tag on the boost to the Samsung brand, there is abundant evidence of the selfie's value in the form of media stories, blog posts, analysis, and even Facebook likes - 2.1 million and counting.

Yet Samsung itself retweeted the photo only once, 20 minutes after Ms. DeGeneres' initial post, and mentioned it again when it broke the Twitter record half an hour later. And the buzz did not seem to bump up Samsung's Twitter followers. While Ms. Degeneres added 1.2 million Twitter followers in the first two days, Samsung tacked on 10,000, about its average for any two days, said Joe Pulizzi, founder of the Content Marketing Institute. "If we're talking about building audiences, and we should be, that's a missed opportunity," he said.

Ms. DeGeneres also didn't mention Samsung in her original tweet. But she did call out Samsung in a thank you retweet from St. Jude's sent after Samsung promised to donate $3 million in honor of the 3 million retweets to two of Ms. DeGeneres' favorite charities, St. Jude's and the Humane Society. The St. Jude's thank you was an Oscar-imitated selfie of actress Marlo Thomas surrounded by St. Jude's kids. Samsung retweeted the St. Jude's photo, and today also retweeted a parody tweet from @TheSimpsons.

So will Samsung's success prompt marketers to move the bar higher for sponsorship demands? Mr. Feldmeth said while marketers may want, or even expect, a Samsung moment, it's useless to simply demand stunts. His advice to other brands is forget trying to recreate or imitate what worked for Samsung and instead focus on what drives the core of their own brand and create the framework for their own moments to happen.

They paid to put themselves in the right place at the right time," said Sharmin Kent, content marketing coordinator at Digital Relevance. "But it was a once-in-a-lifetime tweet."