Mr. Steward looked into creating a sailing channel on the Sky satellite service in Britain, but his idea was soon dead in the water. He would have had to pay £ 85,000 (nearly $150,000) to start the channel and £ 40,000 a month (nearly $70,000), as well as the production costs. That was a lot of money for an untested concept.
But in January, he did introduce a sailing channel, one that is rapidly filling with sailing talk shows, product reviews, programs on sailing techniques and, most important, intense coverage of the sort of smaller races that don't make it onto traditional television…
His new channel, however, will not be available over the air. And it won't be found on cable or even on satellite, at least not yet. The channel, called Sail.tv, is broadcast only on the Internet, which enables video to reach a much larger worldwide audience at a much lower initial cost than a satellite channel. Because ''we didn't have any idea how big the audience would be,'' Mr. Steward said, he wanted to keep his expenses as low as possible. ''Internet television is an investment we can grow into,'' he said.
In the last six months, major media companies have received much attention for starting to move their own programming online, whether downloads for video iPods or streaming programs that can be watched over high-speed Internet connections.
Perhaps more interesting -- and, arguably, more important -- are the thousands of producers whose programming would never make it into prime time but who have very dedicated small audiences. It's a phenomenon that could be called slivercasting….
''We're adding two or three new channels a week,'' said Iolo Jones, the chief executive of NarrowStep, a company in London that provides technology and support for specialized Webcasts. Among his clients is Sail.tv, which says it attracted 70,000 viewers in its first month.
NEARLY 15 years ago, when the advent of digital cable offered the possibility of 500 channels, many people were skeptical that there would be enough programs to fill them. But then came specialized broadcasters -- including the Speed Channel (for auto racing fans), the Military Channel and Home and Garden Television -- and now cable and satellite systems are largely full.
''It has become almost impossible for a channel to increase its distribution the old way,'' said Lauren Zalaznick, the president of Bravo and Trio, two cable channels owned by NBC Universal. ''To get distribution it takes a lot of effort and negotiation. You have to give up a lot to get very little.''
Indeed, after DirecTV dropped Trio, a channel devoted to pop culture, among other things, Ms. Zalaznick decided to move it from pay-TV systems to the Internet. ''To survive we had to find a new way,'' she said. The new way, she quickly realized, could also help Trio resolve its identity crisis. The cable channel mixed documentaries about pop culture, original music programming, reruns of obscure television shows and a fair bit of programming aimed at gay and lesbian viewers.
Moving to the Internet allowed her to break Trio into three distinct sites; they will be introduced over the rest of this year. One, called TrioTV.com, will have the music and pop culture programming. Another, BrilliantButCancelled.com, will have the old TV shows. And the third, OutZone.com, will have gay and lesbian programming created in conjunction with PlanetOut, a media and entertainment company focused on that audience.
Other big media companies are also creating narrower Internet extensions of their channels. Scripps Networks, which runs the HGTV network, for example, created HGTVPro, with programming aimed at contractors and builders.
