By the time the curtain came down on the upfronts Thursday, 16 of the 36 new scripted shows added to the programming lineups of the big four broadcast networks--CBS Corp, Walt Disney Co's ABC, News Corp's Fox and Comcast Corp's NBC--were comedies.

Upfront week is the television industry's annual rite at which networks preview upcoming shows in hopes of getting them to buy commercial time in advance.

Sitcoms led a much broader trend of heavy investment in original programming among the broadcast networks, as they aimed to justify their hefty advertising hauls in a world where viewers' time is increasingly fragmented by online video and social media. The big four networks plus Univision and CW are expected to collect about $9.2 billion from this year's upfronts, a rise of 3 percent over last year.

The heavy bet on original scripted shows also has residual benefits thanks to insurgent companies like Netflix Inc, which have shown an appetite to not only compete, but also pay top dollar for the syndication rights to such programming.

"We're seeing a lot of comedy added and a lot less new reality shows," said Needham analyst Laura Martin. "This is good for the TV ecosystem because TV has to have good syndication windows to sell on shows to other networks. Reality has no library value."

In an effort to shake off their ratings cobwebs, ABC and NBC, who have long ranked third and fourth in the ratings, respectively, made the most significant revamps to their schedules.

ABC is adding 10 new shows to its schedule including six dramas and four comedies. Two of the network's new dramas, "666 Park Avenue" and "The Last Resort," received positive buzz from media buyers who attended ABC's upfront presentation.

NBC -- which most needs a hit -- unsurprisingly added 16 new shows to its lineup, the largest number of any network. Among the highlights was "Animal Practice," a sitcom set in a veterinary clinic that NBC tried to generate buzz for by bringing one of the stars--a monkey named Crystal--to its upfront presentation Monday.

Indeed, NBC is making the biggest bet of any network on comedies, scheduling sitcoms on four out of five nights next season.

Media buyers also had high hopes for J.J. Abrams' science fiction drama "Revolution," though the networks have tried and failed over the last few years to replicate the magic of "Lost," the other Abrams-produced show that launched TV's science fiction fascination.

In contrast to NBC, CBS Corp's eponymous network, the top-rated network in terms of total viewers, has the strongest returning lineup and is therefore in least need of new shows, adding only four, three dramas and one comedy, to its schedule for the new season, the least of any network.

The best received of its shows were "Vegas," a new period drama starring Dennis Quaid in sixties Las Vegas, and "Partners," its lone new sitcom from the original creators of hit comedy "Will & Grace" that has a similar straight-gay buddy relationship as its theme.

Already featuring a strong comedy lineup with "Two and a Half Men," "Big Bang Theory," and "Mike and Molly," CBS boss Les Moonves decided against adding more to his schedule despite the fact that they can help bring younger viewers to the network. CBS' audience is the oldest on TV, with an average age of more than 55 years old.

"We looked at going to eight comedies but felt we already had a great schedule," Moonves said.

For its part, Fox, which trails CBS in overall ratings, added nine shows, including three sitcoms, two dramas, three reality/game shows, and one animation show.

But the biggest news from FOX didn't involve new shows, but a new judge. "X-Factor" producer Simon Cowell appeared on stage Tuesday to announce that Britney Spears and Demi Lovato, who appeared alongside Cowell, had signed on as judges for next season after weeks of press speculation.

FOX also drew applause from advertisers for luring veteran Hollywood star Kevin Bacon to TV for the first time ever for its new serial killer drama "The Following."

"Our audience has consistently asked, '"Where's the next '24'?"' I think we found it," said FOX Entertainment president Kevin Reilly.

The addition of movie stars like Bacon, Quaid, and Lucy Liu, who will star in a new CBS show called "Elementary," is seen as an important trend for the broadcast networks since the perception is that they have been losing buzz and mind share to much smaller networks like AMC, home to award-winning shows such as "Mad Men" and "Breaking Bad." That's to say nothing of insurgent newcomers like Hulu, Google's YouTube, or Yahoo Inc. who are luring stars like Tom Hanks and Katie Couric to digital video by investing heavily in original content creation.

"This isn't new to this year, the networks understand that there's all this development on the other side," said Mediacom Chicago managing director Matt Schwach.

LOSERS

With so many holes to fill, NBC and ABC inevitably also had some of the losers at this week's upfronts, with many of their new shows and schedule changes not going over well with critics and other media watchers.

Horizon Media analyst Brad Adgate said NBC's move to extend its hit talent show "The Voice" by an hour on Tuesday night might be 60 minutes too much for audiences to bear.

"I think they're going to kill 'The Voice' with over exposure," said Adgate.

Adgate also wasn't a fan of ABC's new sitcom "The Neighbors," about an alien family living among humans, which the network plans to air after its hit "Modern Family" on Wednesday night.

But from the TV industry's point of view one person was a bigger loser than any show previewed during the upfronts: DISH Network Corp chairman Charlie Ergen. Network executives are hopping mad at Ergen's launch of a DVR called the "Hopper" that allows viewers to entirely skip over rather than fast-forward through commercials.

The industry was collectively appalled that Ergen would attempt to undermine their key revenue stream of advertising.

"I do find it surprising that they're going to do that to their largest content provider, I mean, more broadcast is watched on their service than anyone else, and this is how the shows are paid for," said Peter Rice, chairman of FOX Entertainment.

CBS' Moonves was even more emphatic. "It's preposterous, they can't do this," Moonves said. "How does Charlie expect us to pay for the programming?"

(Reporting By Yinka Adegoke and Liana B. Baker; Editing by Peter Lauria and M.D. Golan)

• A Permanent Economic Emergency