The new breed of content aggregators is among the biggest bets in online media. These companies are assembling content from hundreds of thousands of contributors, optimizing it on the search engines so it is easily found and syndicating it.

Demand Media is probably the biggest company in the space. But others include Examiner.com, which has a distinctly local/vertical tilt, and Associated Content.

Associated Content CEO Patrick Keane talked with us last week. Keane, a former analyst with Jupiter Communications who has since had major roles with Google and CBS, says the game is all about cost-effective, scalable content generation. “We want to own event content around where ads are found,” he says. The company can also develop content on a custom basis — something it has done for Reuters, Hachette as well as major advertisers, such as Procter & Gamble and Toyota.

Publishers — which Keane calls “the owners of audience” — can increasingly see the value of unique content creation assets, he says. AOL, for instance, owns less than 10 percent of its content. Yahoo’s percentage of ownership may not be much higher.

For such sites, local content is a key differentiator, especially since so much of it has a utility angle. “We see more and more contributors contributing content on a localized basis,” says Keane. Consequently, one of Associated Content’s big initiatives is to find, discern and empower contributors on the basis of local DNA.

Keane notes that Associated Content, which has 60 employees, has 350,000 contributors. Perhaps 40,000, for instance, are in the greater Boston area. They can submit restaurant reviews, local school reviews and other local content, he suggests. That would fit in with the identity of some of the contributors.

A third of the contributors are mercenary agents settling for the upfront, per article fee of $1.50 to $2.00, notes Keane. Another third are experts of some kind who want to have a professional voice about what they’ve done, such as an accountant in Phoenix. The remaining third are “social media Web freaks. They create community about what they write about.”

While Associated Content is a powerful site onto itself, ranked 39th overall by Quantcast, Keane emphasizes that it is not about “being monolithic with singular content. For us, we are 2 million destinations. It is about how people use content in certain way.”

True to his roots at Google — and investor Tim Armstrong’s roots at Google — Keane says much of the equation ultimately revolves around search. He notes that 80 percent to 85 percent of the site’s content is found via natural search. “We are about search effectiveness and having accountability to brand advertising. It is not about the best cordless drill. It is about people who are predisposed to buy the drill,” he says.

“We are increasingly a navigation hub,” Keane adds. “We’re playing in that world as opposed to super bowl ads.” Consequently, a major effort for the company is to achieve higher page rankings over time by incorporating lots of different kinds of content, including images, slide shows, video and real-time search.

Seventy percent of the company’s 2 million content pieces continue to be text-based, although that percentage might be slightly declining.Text indexes better through natural search and it is faster to render, says Keane.