Brands have long turned to so-called YouTube stars to make videos that resonate with their devoted audiences. Now YouTube network Fullscreen looks to facilitate that matchmaking with a new service that pairs its 15,000-plus creators with any brand paying to use its tools and could step on agencies' toes.

Akin to an agency or vendor RFP, a brand can post a bulletin to Fullscreen detailing the audience it's looking to attract, any creative parameters, budget and timing. Fullscreen pings its network of 15,000-plus creators who can pitch the brand on a campaign idea and work out a pay-for-performance deal.

The TaskRabbit-like service called Fullscreen Gorilla is one of a number of initial apps aimed at anyone creating content for YouTube, particularly brands whose YouTube channels are chock full of repurposed TV spots.

"Think about Twitter. If all a brand ever did on Twitter was buy Promoted Tweets, they would fail. They have to also tweet themselves. Think about YouTube in the same light," said Fullscreen CEO and founder George Strompolos.

Mr. Strompolos acknowledged that YouTube's work with brands on the content side via the YouTube BrandLab, Video Creation Marketplace and upcoming pilot program sparked the thinking about marketers as content creators. However "we've found that over the long term to build something sustainable creators and brands need a long-term partner. That's where we come in. A lot of heavy lifting goes into building a real content presence on YouTube," he said.

Agencies traditionally carry much of that load, but Fullscreen's service could lead their clients to work Fullscreen's creators directly and leave the agencies in a lurch (though brands could elect to involve their agencies). Tasked with keeping up with YouTube's growing partner ecosystem and at times lacking the infrastructure to do so, "agencies are already being squeezed out of the equation," said Digitas SVP-partnerships, content and social John McCarus. "If you want to lead clients, you need to figure out how to be at the tip of the spear with all new offerings."

Fullscreen also wants a piece of the advertising side of YouTube. The company keeps an eye on roughly 2 million of the most active YouTube channels and approximately 1 million new videos uploaded each day in order to report performance metrics such as views, shares, comments and which sites those videos are embedded on most frequently. Brands can apply those insights to determining which channels or videos to advertise against when placing their media buys through Fullscreen.

For non-brand YouTube creators, Fullscreen's new tool set seeks to improve on the Fullscreen Dashboard that has been around for two years, helping to manage their content and monitor how it performs. Creators can use it to access earnings reports on how much revenue they've received from sponsorships, merchandise sales or through ads sold by Fullscreen and taking into account any revenue-share or financing deals those creators may have in place with Fullscreen.

Fullscreen creators can also connect with one another through a new social service that builds on the company's pre-existing forums and adds a Match.com element to identify which creators might be interested in meeting and potentially collaborating. Mr. Strompolos envisioned this social layer evolving to resemble a more communal Craigslist for filmmakers to lend, rent or sell equipment and services.