The big Digg rig

Now, dubious Internet marketers are planting stories, paying people to promote items, and otherwise trying to manipulate rankings on Digg and other so-called social-media sites like Reddit and Delicious to drum up more links to their Web sites and thus more business, experts say.

"People are trying to basically take advantage of Digg by artificially promoting a story with fake diggers or some other methodology of link swapping," Digg Chief Executive Jay Adelson said.

Unlike traditional news sites where editors decide what the news is, Digg emerged two years ago as an alternative where readers post links to stories from other Web sites that they think are newsworthy. The users hit a "digg" button if they like it or a "bury it" button if they don't like it. The most popular stories appear on the front page. Users are encouraged to comment on stories, and they can give comments a "thumbs up" or "thumbs down."

The egalitarian nature of these aggregation sites has led a number of online publications, including CNET News.com, to add "Digg" and "Delicious" buttons that allow their own readers to recommend their stories to other users of the aggregation sites.

So it shouldn't be a surprise that marketers and spammers are a half-step behind. Since popular stories on Digg get linked to by blogs and other sites, marketers are doing everything they can to get content from their sites featured on Digg. The more links back to a Web site, the more it rises in search engine rankings and thus the more money that site can make.

Some marketers offer "content generation services," where they sell stories to Web sites for the sole purpose of getting them submitted to Digg and other sites. This combination of spam and blogs is called "splogs." The stories often feature topics and keywords in headlines that are likely to appeal to the Digg crowd, such as "geeks" and "Apple."

Lazier but still tricky marketers merely scrape content off legitimate sites to put up on their own sites in a technique called "link jacking." In essence, they are hijacking the links that should go back to the original site, experts say.

In a posting last week titled "The Spam Farms of the Social Web," blogger Niall Kennedy detailed how a suspicious item recently made it among the top five stories on Digg before the community "buried" it. The Digg user submission links to a story entitled "Geek's Guide to Getting in Shape: 13 Surefire Tips" written by "Dental Geek" for the i-Dental Resources blog. The blog site has links to other pages with ads that offer content creation marketing services and which collect money for dental plans sold, Kennedy said.

Digg isn't alone in these problems. News aggregator Reddit and Delicious, where users swap Internet bookmarks, are also susceptible, Kennedy said.

Thankfully, "the weight loss story never made it off the new page on Reddit," said Chris Slowe, senior programmer at Reddit, which was recently acquired by Conde Nast, owner of Wired Digital.

Slowe said he is aware of attempts to manipulate aggregation sites but said Reddit users are good at "self policing." For instance, users will band together and vote down stories promoted by suspicious users, he said.

A representative for Delicious, which is owned by Yahoo, had no comment on whether or not there have been attempts to rig that site.

Money driving ingenuity
Companies charge as much as $15,000 to get content up on Digg, said Neil Patel, chief technology officer at the Internet marketing firm ACS. If a story becomes popular on Digg and generates links back to a marketer's Web site, that site may rise in search engine results and will not have to spend money on search advertising, he said.

Another way to get Web links to a suspicious site is to get inside help from users at a social-media site. For instance, spammers have tried to infiltrate Digg to build up reputations and promote stories for marketers, experts say.

Other scammers are trying other ways to buy votes. A site dubbed "User/Submitter," purports to pay people 50 cents for digging three stories and charges $20 for each story submitted to the site, plus $1 for every vote it gets. The Spike the Vote Web site boasts that it is a "bulletproof way to cheat Digg" and offers a point system for Digg users to submit and dig stories. And Friendly Vote bills itself as an "online resource for Web masters" to improve their marketing on sites like Digg and Delicious.

"Digg has become a big enough phenomenon that it does move ideas and in some cases generates enough traction that people can then buy into a product or a stock," said Kennedy, an independent researcher working on search technologies. "A fake story will affect the (PlayStation maker) Sony brand."

Kennedy was referring to an item headlined "Just out from Reuters 650,000 PS3s to be recalled!!" posted on Digg on November 20 that made it to the front page within hours, according to a blog posting titled "Limitations of Socially Driven News," written by Digg user Muhammad Saleem.

Digg executives say they are on top of the situation.

"There is technical information that only we could know that flags us when someone is attempting to manipulate" stories and rankings, said Digg's Adelson. "It happens every single day." Adelson declined to go into details on how the system works.

In addition, Digg's 680,000 registered users serve as cops and fact-checkers, he said. "By merging the algorithms and the people I believe we have a foolproof system."

For now, it's a cat-and-mouse game for Digg to stay on top of the rigging attempts.

"Digg and others are working hard to deal with this kind of abuse," Jupiter Research analyst Barry Parr wrote on his blog this week. "But until it is eliminated, the credibility of social-news sites will be in question."