Vaporvue launches this week, a subscription site with on-demand access to streaming video of extreme sports like surfing, skiing, and snowboarding. The service launched with a $9.99 monthly subscription and $99.99 annual price. Filmmaker Ira Opper started the site, which will stream movies, documentaries and TV series on multiple devices, including Roku, desktop computers, iPhone, iPad, smartphones and tablet.There is not a lot of extreme sports streaming video available online, so the $9.99, while risky, seems fair. But if bigger, genre-agnostic video streaming sites like Netflix or Amazon decide to start offering extreme sports, Vaporvue could end up with a short life. After all, who would want to pay $9.99 for access only to extreme sports when the same amount would get you extreme sports, original content and other shows?And while we usually advocate paid trials, the site’s 7-day free trial is smart since that’s the industry standard set by Netflix. Furthermore, the site is likely to see a high conversion rate from trial to paid because it requires a credit card at sign-up.What do you think? Is this a smart “niche” launch, or one that’s likely to be engulfed by the Big Two of video streaming?