Video-sharing website YouTube celebrates its fifth birthday today with the news that it receives more than two billion hits daily.

That's almost double the number of people who tune into ABC, NBC, and CBS combined, says YouTube's owner Google. It's also a huge leap from the 1 billion-plus daily views the site said it was getting in October.

The average YouTube viewer stays on the site for about 15 minutes a day, compared to TV's five hours. YouTube is hoping to narrow the gap – and cash in on the trend toward Internet television – by adding full-length movies, concerts and live sporting events. That's a far cry from the 19-second 'Me at the Zoo' video, the site's first offering, which was posted by co-founder Jawed Karim.(It's also a far cry from guys dancing on treadmills and babies doing cute things, the sort of content for which the site is infamous.)

"The day is coming when people won't think of online video as being separate from TV," Shishir Mehrotra, who runs YouTube's advertising programs as director of product management, told the Los Angeles Times. "The lines are blurring in both directions. From the viewer's perspective, there are many ways to watch content on their TV, and TV content on the Internet.'

Catharine P. Taylor, a media blogger at news website, told BBC News: "YouTube really is a phenomenon and is very much part of popular culture. It really is a game changer because it gives everybody a platform to broadcast from. There are many examples where an average citizen has become a big hit on YouTube and that is something that would have been impossible to contemplate five, six years ago."

The site – a perennial money-pit – has increased its revenue, the New York Times said. The ad space on YouTube's home pages was sold out every day in 20 countries in the end of 2009, and the number of advertisers using display ads has increased tenfold, according to Bloomberg News. Analysts say the site could start contributing to Google's bottom line this year. 

YouTube is also going to change a lot, experts say.

"I think we will see it on more devices and see it used more for live streaming,' Ryan Lawler of video site told BBC News. 'There are real opportunities for it to become a traditional content distributor like the cable channels. YouTube streams make up around 40 percent of all online video watched in the U.S., so there is massive scale there and lot of opportunity."

Still, the site faces big hurdles with advertisers, many of whom are leery of putting their ads next to content viewers could find offensive. "For the sort of brand advertiser that's willing to spend a lot of money, it needs to be trusted content," eMarketer analyst David Hallerman told Bloomberg. "It's not even the first inning yet." (Of course, YouTube's user uploaded content means you can still advertise your business for free on YouTube; here's how.)