Remember CinemaNow, the Marina Del Rey-based movie-downloads service backed by Lionsgate, Microsoft, and Cisco, among others? Its video-streaming service has been left in the shadows by Apple, Netflix and, but CinemaNow's found a way to survive: porn.

On CinemaNow's company background page, it lists Hollywood studios such as 20th Century Fox and Disney as well as TV networks ABC and NBC as suppliers. But there are a few more. Like Vivid and Hustler, for starters. Also: Red Light District, Evil Angel Video, New Sensations and Elegant Angel.

How big a part of CinemaNow's business is porn? CinemaNow marketing director Lawrence Novitch told me "it's a big piece of the pie" but didn't provide exact figures. However, traffic stats provide a clue. When CinemaNow customers go to rent an adult film, they're redirected to a separate domain, One way to see approximately how much of the company's business is porn is to compare traffic to and

As you can see, for most of 2007, traffic to exceeded considerably. Traffic to each site is about even now, though puts AllAdultChannel's "people count" slightly higher. If that's a good predictor of usage, then porn's piece of CinemaNow's pie is big indeed.

Not that we blame them for a second. Porn could be CinemaNow's secret weapon in the online-video battle. In a comparison test between online movie rental stores Amazon Unbox, Apple iTunes, Netflix and CinemaNow, Bloomberg News today rated CinemaNow the highest with an 8/10. Bloomberg's writer rewarded the site for its mix of new and old titles and its easy user interface. (The review did not clarify whether the site can be operated one-handed.)

The porn business has always been the first to monetize new technologies on the Internet. So while Apple, and Netflix wait around for watching movies online to become a mainstream activity — some go as far as to predict Netflix won't survive to see it happen — Microsoft, Cisco, Lionsgate, and CinemaNow's other backers may come to know the true meaning of "money shot."