Much bandwidth has been consumed discussing the effects of Facebook's recent algorithm change to favor sites offering "high quality" content. It's been said to hurt viral sites like Upworthy -- a notion the site's founders have denied -- while rewarding other publishers including Mental Floss.

But little has been said on how publishers seeing a traffic bump actually make money from those additional eyeballs.

Social media referrals now account for nearly 50% of overall traffic to some publishers' sites. Facebook is eclipsing all others as the top traffic driver, according to a report last year from Shareaholic, a company that makes social media sharing tools.

Publishers are largely cashing in on this traffic through extra exposure for existing display ads, but many have created ad products to specifically target referral traffic. The New York Times, for example, sells ad packages that appear specifically for visitors who arrive through social media such as Twitter and Facebook. Gawker Media offers ad packages that treat article pages, where many social visitors first arrive, like the homepage, which for many sites is where you'll find the biggest and best ad programs.

A new approach from ad tech company 33Across is looking to "democratize" this strategy across a broader network of publishers' sites, according to the company CEO Eric Wheeler. The product serves a large additional ad to visitors who reach a site through Facebook, Twitter, Google and other sources. The display ad pushes in from the left without obscuring the text of an article. It's able to serve relevant ads on desktop and tablet using what it calls intent signals, such as content on a page, other people who have visited the site and the referral source, according to Mr. Wheeler.

While the ads can include rich-media such as video, some media executives shrugged at the idea. It is, after all, just another banner ad at a time when native advertising is all the rage.

Mr. Wheeler said the ads are seeing 1.5% average click-through rates and helping publishers fetch incremental ad revenue because they appear on a site along with any other display units. "When people come through search or social media, their site behavior is kind of frustrating because they come in, see the page and leave," he said. "We're reaching them when they come in."

Serving ads to referral sources could also undermine what publishers are doing in the native-ad space. A brand that sponsors an article -- whether in the form of an advertorial or simple ad space around an editorial article -- may not be hungry, exactly, for yet another marketer's message to push in. But Mr. Wheeler said publishers have the ability to determine what pages they wish to show the ad units.

The company's efforts mark the latest attempt by ad tech vendors to help publishers make money from social visits. A service from Assetize had worked with publishers to insert an advertising bar atop pages that were shouted out in participating Twitter feeds. The bar included space for not only a marketer's message, but also the publisher's own branding and buttons to encourage retweets.

But selling ads to marketers didn't prove fruitful for publishers because their tweets weren't seeing enormous scale, according to Assetize co-founder Saif Ajani. Assetize retrenched, giving the concept a new name -- SharedBy.com -- along with a new approach, where bloggers, authors and even real estate agents use the space to promote themselves and their products and services.

Mr. Wheeler said 33Across has more than a billion pageviews across the publishers already using its product. Two years ago, 33Across bought Tynt, a social content sharing service that helped publishers track content that was copy and pasted into emails and social media via java script on their sites. Tynt's code is embedded on more than 625,000 publishers' sites globally; 33Across hopes to persuade those sites to use its new ad product. Already, the company has signed on over 200 publishers, including personal finance and business publication Kiplinger, according to Mr. Wheeler.

The company plans to roll additional ad products that will include retargeting and allow for programmatic ad buying. Another forthcoming product serves ads to tablet users that zoom in. "It's like showing a TV ad when you know people are in the room," Mr. Wheeler said.