“They swear like sailors, but boy, they’re smart.”

That’s how NPR strategist Andy Carvin described the 1.4 million fans who comment and share stories through NPR’s Facebook page. The page — originally created by an NPR enthusiast from Canada — is one of the more popular media outlets on Facebook.

Carvin talked about NPR’s approach to Facebook last night as part of an ONA-sponsored media event at Facebook headquarters in Palo Alto.

“We have better comments on Facebook than on our own site,” Carvin said, in response to an audience question about whether NPR was reluctant to divert audience engagement from its own homepage to an outside site.

In part, Carvin said, that’s because comments on NPR.org tend to be highly political and polarized, and because comments sections are also constantly beset by spammers. For many news stories — particularly ones where reporters are filing from abroad — the author of the story isn’t able to moderate the comment thread and, so, to help guide conversation and build community. NPR’s blogs, on the other hand, where this moderation happens, tend to be more conversational and interactive.

But Carvin also emphasized the importance of audience expectations. “They still see our site as mainly dedicated to consuming news,” he said. Facebook, on the other hand, is a web venue in which people are used to chatting with their family and friends.

The result, Carvin said, is that conversations on NPR’s Facebook page can become surprisingly intimate. A story about stillborn children, for instance, attracted comments from “dozens and dozens” of families who talked about their own experiences. “That didn’t happen on our site,” Carvin said.

The referral traffic on NPR’s Facebook page has grown from 1.5 million to 4.5 million pageviews a month, Carvin said. While that traffic used to result largely from fans clicking on links that NPR posted, now as much as half of it comes from links that fans decide to share themselves.

The articles that Carvin and his team post to the Facebook site aren’t typically the day’s lead stories or items of big breaking news. Instead, Carvin said, the question he asks before posting is, “Will our friends want to talk about this?”

It turns out that NPR’s Facebook fans like arts and culture reporting and multimedia stories with video (but not, surprisingly, with audio). In a survey of NPR’s Facebook fans published this summer — which attracted 40,000 responses, the most of any survey NPR has conducted — the outlet found that its science stories are extremely popular on Facebook, but tech stories aren’t. And there’s some hypocrisy at play, as well: While, when surveyed, NPR’s Facebook fans claimed to value foreign affairs and economic reporting, they often won’t actually click through to those stories.

The survey also confirmed that fans thought the tone of the Facebook comments, swearing and all, was appropriate, and that having 7 to 10 articles posted a day wasn’t too much for them. The Facebook fans are also some of NPR’s most devoted listeners, with 70 percent of them tuning into their local NPR station — and averaging 2 hours of NPR consumption a day. Fifty-five percent also visit NPR’s website on a regular basis.

In other words, NPR’s Facebook page is a complement to, not a substitute for, other kinds of NPR news consumption.

While Carvin — very politely, given the venue — suggested that Twitter’s search function was more useful than Facebook’s for journalists, he said that the Facebook page has become “one of our most important sourcing tools.” NPR posts about three or four queries a week — asking, for instance, for jobless 20-somethings who might be willing to talk to an NPR reporter about their experiences. And NPR’s Facebook fans turn out to be very willing to respond. Typical sourcing requests attract 750 to 800 responses, Carvin said. Getting less than 300 is rare.

And of the 140 to 150 sourcing questions asked so far, he said, only two or three have had no results, an extremely high success rate. Facebook was even crucial in Carvin’s recent reporting on Tunisia, even though his query received fewer than 40 responses — in part, Carvin said, because many of those with information were scared to post it on a public site.

One of the most important choices NPR has made in regard to the Facebook page is a willingness to let fans set the tone of what will happen. “We feel like it’s as much theirs as it is ours,” Carvin said. “If they want to swear like sailors, [they can]. We  don’t block comments just because there’s swearing, or even if they’re being snarky.” While NPR staffers will delete hate speech in the comments, they’ll let criticism stand. And Facebook users themselves will often take care of trolls or fake accounts by reporting them to Facebook on their own.

As for criticism of NPR itself, Carvin said, they’ve struck a balance. Fans can’t post on the Facebook wall, which is defined by official NPR postings. But the outlet has given fans free reign over the “Discussions” section on the Facebook page — so users who want to continue to blast NPR over Juan Williams’ firing can do so, just in a slightly separate venue.