No wonder providers are protesting. “Your cost of production — which would including shooting, location, lights, cameras, sounds and editing — is going to be thousands of dollars per video,” said Mr. Calacanis, who stopped investing in his YouTube operation in July and turned his attention to Inside.com, a mobile news app he is developing. “For 10 ‘advertiser friendly’ videos of YouTube length, you would spend at least $25,000 to $75,000. This means you are in deep in the red before you take into account your talent.”

Mr. Kyncl of YouTube said that aspiring content creators who looked only at the cost equation were taking the wrong approach. What YouTube offers, he said, is a chance to build a worldwide viewership that can lead to income from sources other than direct ads. As an example of a successful switchover, he points to Bassem Youssef, a Cairo heart surgeon, who offered a show something like “The Daily Show With Jon Stewart,” won five million viewers in a few months and got a contract with an Egyptian television channel. Or there is Awesomeness TV, a network for teenagers, which was built for YouTube but now has content on Nickelodeon and intends to use YouTube as a “farm team” for TV.

“The more successful you are on YouTube,” Mr. Kyncl said, “the more you should think about diversifying.”

Olga Kay grew up in rural Russia until her family ran out of money and she went to work for a circus. She learned to juggle and eventually got a visa to come to the United States to join the Ringling Brothers and Barnum & Bailey circus. She began to get work in commercials — for example, juggling glasses in a Smirnoff Vodka ad. In 2002, she moved to Hollywood, looking for a career in show business.

At the time, YouTube was a burgeoning phenomenon, and Ms. Kay was sucked in. In 2006, she began a video blog about her daily life and soon had tens of thousands of followers. In 2009, she added a second channel, featuring skits with characters like Emo Girl, a self-involved, overly emotional teenager whom Ms. Kay plays by wearing a black wig and lots of black eyeliner. Her first Emo Girl video, “Doctors Want to Have Sex With You,” got a half-million views in about two weeks.

There was “no breakout moment,” she says, just a constant push to expand. “I am always growing through real avenues and not counting on a viral hit.”