The service lets you send video clips via MMS from your phone - a feature that's lacking in YouTube and many of its rivals. According to SelfcastTV founder Suranga Chandratillake (left), that's because they're based in the US, where video-capable cameraphones are still relatively thin on the ground.
"That's filtered through to the sharing sites, so none of them have any real support for mobile phones," he says. "Some support email-based uploads because laptops with Wi-Fi are popular, but that's it."
SelfcastTV started life last year as an offshoot of video search engine Blinkx, allowing people to upload their own video clips. The popularity of this feature co-incided with the rise of video-sharing sites like YouTube, and the fact that 80% of people using the Blinkx version convinced Chandratillake there was room for a UK-focused competitor.
Its commercial launch was this week, although you may have come across its soft-launch during the World Cup, when disgraced football pundit Ron Atkinson used it to air his views on the tournament when no broadcaster would employ him ("It wasn't a promotional stunt," says Chandratillake. "He came of his own accord, but then we realised the value of it!")
For the moment, the mobile aspect is a pretty powerful unique selling point, although it's surely only a matter of time before YouTube integrates mobile, given the rapid rollout of 3G handsets from operators Verizon Wireless, Sprint Nextel and MVNOs like Helio and Amp'd Mobile.
Chandratillake says SelfcastTV has a few more aces up its sleeve. For example, there's an innovative 'channel' feature to group video clips and watch them together.
"Users or our team can create groupings of relevant content, almost like a playlist, and then when you watch that channel, you can hit a button called Movie Mode, where the videos play in full-screen back-to-back, while you sit back and just watch," says Chandratillake.
If you're a traditional TV broadcaster, you should be sitting bolt upright at the thought of broadband users constructing their own 30-minute telly sessions from other people's clips, rather than settling down on the sofa to watch Love Island. Although with initiatives like MTV's Flux (covered here earlier this week), it's clear the warning hasn't gone unheeded.
Chandratillake is keen to play on SelfcastTV's British feel, which although narrowing the site's appeal internationally, in theory will establish a stronger connection to its users. He says that the logical result of a video-sharing site with 80% of its users in the UK will be plenty of 'British' content. That'll be football, beer, boobs and bulldogs then. Ideally all four at once.
"I wouldn't be surprised if we see more of this verticalisation of sharing sites by geography or topic," says Chandratillake. "Some might focus on sports, or TV for example. That's the way we'll look to go. We'll try to match what our user base is interested in and wants to do."
Trouble is, what if they want to upload copyrighted content? It's arguable that YouTube owes much of its success to people uploading TV shows, advertisements, wobbly cameraphone videos taken at music gigs, and web-loons jumping around lip-synching to Britney Spears videos. All of which are frowned upon by many record labels, broadcasters and rights-owners.
"There's definitely a cheap win that can be made from turning a blind eye towards commercial content, but in reality it doesn't get you anywhere," says Chandratillake. "If your business is based on that content, when it goes away your users will leave too."
SelfcastTV will be using some of the filtering and matching technology developed for Blinkx to identify and remove copyright content posted by users more quickly and more efficiently than its rivals. But isn't there an argument that much of this stuff - the lip-synching and gig videos at least - is actually beneficial to the original rights-owners?
"Morally and culturally there is absolutely a grey area, but legally there isn't," says Chandratillake. "It's very clear what is and isn't allowed. So we will campaign and talk to people behind closed doors about why they should let users do more interactive things with their content, but while the law remains as it is..."
Happily, some rights-owners are waking up to the potential - for example the current promotion for Robbie Williams' new 'Rudebox' single, where fans were invited to download the song's intro and video themselves dancing about to it, then upload the results. In theory, sites like SelfcastTV could be partners for this sort of thing in the future.
But the burning question remains: how do you make money from video-sharing, particularly given the high bandwidth costs of hosting and streaming video content? Chandratillake says in the short-term, Blinkx makes enough money to support SelfcastTV while it picks up users. But that's not sustainable in the long-term, surely? Chandratillake agrees.
"In the longer term, if this ends up being as big as or bigger than our main business, we'll have to think harder about how we monetize it," he says. "We do have ad serving technology, not just text ads like YouTube, but the ability to put video and image ads in and around the content. So we'll experiment with that, but for now it's fine."