Who's the bigger star: comedian Jimmy Fallon or YouTube sensation Connor Franta?
Seems like a no-brainer in favor of the NBC late-night host and former "Saturday Night Live" mainstay.
But consider how the two perform on social media. In an age when advertisers prize engagement (lingo for when someone "likes" your Facebook post, "shares" your tweet or "comments" on your Instagram picture), Franta appears to have an edge.
Those are the findings of Venice-based marketing start-up Zefr, which compared the reach of traditional stars like Fallon against social media influencers like Franta.
The company determined an "engagement rate" by dividing an individual's engagements with the number of followers and subscribers they maintain on Facebook, Twitter, Instagram, Vine and YouTube.
Even though Fallon's fan base is more than three times larger than Franta's at about 40 million, the network television host's engagement rate pales in comparison at 3.1% versus Franta's 16%.
That's important to advertisers who get more bang for their buck when online followings spread the word for free by being actively engaged.
"User activity reveals in real time what's resonating and what isn't by how individuals interact and engage with content," Zefr's report said. "The value of engagement cannot be understated. It is quite literally the data equivalent of millions of people telling brands and content owners exactly what they care about most."
That's an important shift as digital content continues to challenge traditional TV for ad spending.
Advertisers paid $68.5 billion for TV placements last year, a modest increase of about 3.5% from 2013, according to eMarketer.
Digital advertising, on the other hand, grew nearly 18% over the same period to $50.7 billion. Online videos alone saw advertising spending soar 52% between 2013 and 2014 to $5.8 billion.
There to reap the benefits are previously unknown stars who have amassed followings on social media over the years, helping redefine what it means to be a celebrity. If stardom was bolstered in the past by building walls between fans and fueling a mystique, it's now being driven by increasing accessibility.
"These people are actively asking to be engaged with fans," said Zack James, Zefr's co-founder. "The fan base is more engaged because there's not a lot barriers. It's a different mind-set. People feel closer to their stars."