Upworthy, a nearly two-year-old site that curates and repackages content with headlines built to share, has charged into the media landscape as one of the most talked about (and imitated) viral media sites.

Founded by former MoveOn.org Executive Director Eli Pariser and former Onion Managing Editor Peter Koechley, Upworthy says its goal is to draw attention to meaningful topics, from body image issues caused by Barbie dolls to the plight of torture victims. One recent post -- with the headline "I Got A Bus Earlier, And A Woman Was Being Tortured Right Next To Me" -- shows bus-shelter ads depicting torture victims. Fast Company referred to the site as a "soulful BuzzFeed."

Critics have accused the site of dangling click-bait to draw visitors. But Upworthy argues that pageviews make only a "flimsy" measure in any case, one useful only to sites that deal in banner ads (which, like BuzzFeed, it does not). Upworthy's pitch to advertisers is that it can draw eyeballs -- and social media shares -- to branded content posts in the same way it does for its own stories.

And this week Upworthy moved to show that readers are engaging with the content, not just clicking and potentially wandering off with the page open, with a new metric called attention minutes.

Media companies have long tried to impress advertisers with similar metrics, showing them a range of stats from time on site to social media shares. But Upworthy says attention minutes provides a more telling picture of engagement by looking at several key signals, including whether a video is actually paying, mouse movements and which browser tab is open.

Readers spent an average of more than 7 million attention minutes on Upworthy daily in the fourth quarter of 2013, according to the company. It plans to make the source code for attention minutes public so other sites can gauge their audience involvement the same way.

We spoke with Mr. Pariser, a keynote speaker at the Ad Age Digital Conference coming up in April, about Upworthy's new metric, native advertising and CNN's recent, criticized foray into Upworthy-style headlines. Our conversation has been lightly edited.

Advertising Age: How do you convince brands to accept your metric?

Eli Pariser: The premise of Upworthy has always been: If we build something that's principled and focused on user satisfaction, revenue follows. It doesn't work the other way. Initially we're just applying this metric to ourselves and we'd love to see other people take it up. If all it does is make us much smarter about content we deliver to our users and how they experience it, that'll be big win.

That said, I think the promise of really measuring stuff on the granular level is that we can provide much more interesting data to the folks who we work with. It's not just how many shared this, but what does the attention curve look like for this piece of content.

Ad Age: Why should advertisers care about what you're doing with attention minutes?

Mr. Pariser: Not all pageviews are the same. Pageviews bought on international networks shouldn't count in the same way that pageviews driven by organic sharing do. We're still finding that the folks we're working with want to look at both and that's fine. We think the more they are tuned into the not just getting people on the page, but getting them into the content, the better off we'll all be.

The promise of native advertising is that brands are creating content that readers will really love. This is an honest metric of whether this is really happening. It may not always be flattering, but by optimizing for this you're solving the native advertising problem at a deeper level than you do if you just say we've got a bunch of pageviews -- who knows where they came from or what they do when they get there.

Ad Age: What do you mean by the "native advertising problem"?

Mr. Pariser: How do you actually close the gap between what brands are excited about and what users are excited about? That's the Holy Grail: You provide content that people love so much they want to share it with their friends and it tells a brand story. Metrics like this ought to help close that gap.

Ad Age: This week, CNN drew criticism for tweeting an Upworthy-style headline on a story about rape. Do you slap your forehead when you an organization like CNN doing it this way?

Mr. Pariser: Yeah, there was a head on the desk moment.