NEW YORK (AdAge.com) -- Want to see the trailer for Time Warner's "Superman Returns" without going to your local Cineplex? Just start surfing the web.

Movie studios spent more than $40 million advertising online from January through May, estimates Nielsen/NetRatings AdRelevance, making up 39% of all entertainment spending online. That's up from about $35 million during the same period last year. It's still a fraction of the $1.83 billion studios spent between network and cable TV last year, according to TNS Media Intelligence. But what isn't reflected in those dollar figures is the sheer volume of web video uploaded as content, not ads, and that the studios aren't paying anyone to stream.

Nothing but trailers
Check out hollywood.com, comingsoon.net, movie-list.com, movie-page.com and ez.entertainment.net. Those are just a few of the sites whose main purpose seems to be to give web surfers access to the latest movie trailers.

"While it might not be reflected in total dollars spent, there's absolutely a much greater focus on the internet, and how to create the right content so it will be passed along and shared online," said Adam Fogelson, president-marketing, Universal Pictures. "With a movie like 'King Kong,' we can count on millions of people hunting it down online without spending anything on advertising. That is critically important."

And now that studios have realized fans will seek out trailers online, savvy movie marketers have figured out how to position their trailers as entertainment content in their own right.

"Trailers are big business online," said Paul Dergarabedian, president of box-office tracker Exhibitor Relations. "This is turning out to be a huge boon to the movie industry because it's a relatively cheap way to drive awareness levels, which does translate at the box office."

A million movie streams for Yahoo
Leading web portals such as Yahoo and AOL understand the value of highly anticipated releases, relying on three or four hits a year to generate traffic tidal waves. "A movie like 'Harry Potter' or 'Chronicles of Narnia' is enormous for us," said Erik Flannigan, VP-entertainment programming at AOL. In the month of May alone, AOL's Moviefone and Yahoo Movies drew more than 10 million unique visitors each, according to Nielsen/NetRatings NetView. A Yahoo spokeswoman said those visitors stream roughly a million trailers in an average month.

And while hosting exclusive trailers can create giant traffic bursts, Mr. Flannigan and his counterparts at rival portals know the real potential is in visitor retention. "It's not just about the traffic from a movie like 'Mission Impossible,"' said Wenda Harris Millard, Yahoo's chief advertising sales officer. "More so, it's the opportunity to grow our base of regular Yahoo users."

And if the movie studios don't end up getting free impressions from the likes of Yahoo and AOL, they can still come out ahead online. Big-name brands are signing up to sponsor what is, essentially, movie advertising. In June, Disney announced deals with State Farm, AT&T and Georgia Pacific to sponsor a microsite for its animated movie "Cars," as well as Kodak and Verizon as site sponsors for "Pirates of the Caribbean: Dead Man's Chest."

"Anything related to our films, especially exclusive content, is generating huge interest online," said Brad Davis, VP-ad sales, Disney Online.

Thank broadband
Broadband penetration among active internet users has reached 68%, creating a swell of interest in online video. Of the entire adult online population, 23% claim to have watched streaming video on their computers during the last 30 days, according to Nielsen/NetRatings. Meanwhile, 10.7% report using their computers to watch a movie or movie clip during that time.

"Increases in bandwidth and consumers with broadband connections have meant more people spending more time watching and sharing video online," said Forrester Research senior analyst Peter Kim. "Luckily for studios, movie trailers are a natural fit."

In February, traffic to video-sharing sites such as YouTube and Google Video officially overtook movie sites run by Walt Disney Pictures and Sony Pictures, according to Hitwise. "Now, video sites are over three times the size in market share of visits," said Bill Tancer, general manager of global research at Hitwise.

Charging marketers
Some popular sites like MySpace and YouTube -- which drew 50 million and 12.6 million visitors, respectively, in May alone -- are catching on to the fact that they can charge movie studios for promoting their films. In April, movie moguls Bob and Harvey Weinstein struck a deal with YouTube through their agency Deep Focus to feature the first seven minutes of the thriller "Lucky Number Slevin."

To promote its comic book adaptation "X-Men: The Last Stand," 20th Century Fox recently set aside 8% of its total marketing budget for the web. The MySpace page created for the movie accumulated over 680,000 "friends" during its first week of existence, and now has well into the millions.

While teenagers are still more likely to cite TV as their main source for movie updates, the web isn't far behind, according to a Burst Media survey of more than 1,800 connected teens between the ages of 13 and 17. Twenty-nine percent listed TV first, but 25% cited the internet as the place they go for movie information. That makes the web a more meaningful source for movie and TV news than word of mouth (15.7%) or local newspapers (10.3%).

Though the emerging emphasis online isn't offsetting what studios spend on TV, that tipping point is coming, according to Mr. Kim. "For the upfronts -- which includes entertainment spending -- last year was all talk. This year people are slower to jump into it, but we don't expect spending to change," he said. "Next year we expect to see a shift in spending."

A dollar spent online, however, does not equal to a dollar spent on TV, Mr. Kim added. "Successful viral can cost next to nothing and have a huge impact."