Sacrifices quality
The way I see it, services like this succeed through good marketing hype and sadly this pushes down quality and promotes an inferior product to dominate the market place.
Skype has already done this with a product that's proprietary, not properly supported by the vast majority of VoIP hardware, doesn't integrate well with SIP supporting based mobile phones, and still generally requires a PC to be switched on somewhere to even work. Good marketing and clueless consumers however mean that it's a success.
In many ways they've borrowed the business model of Sky (hmm, hang on, even the name has 'Sky' in it and the font is a bit similar to Sky's as well...).
iPod is another. Whilst the device itself isn't inferior in quality, the music downloads are, but analysts have concluded that people don't want quality, they want convenience. They are right that people want convenience but I feel they are wrong about not wanting quality also. They miss the point that people don't just want to exclusively listen to music on a portable device. I worry that CDs will dissapear some day and the only available music will be on poor bitrate DRM downloads.
Same with broadband video which I suspect will mainly succeed on portable devices partly because of the quality issues and partly due to more analysis which will tell marketing bods that people want portable video. Personally I don't find the idea of watching video on a train or bus particularly attractive, but if the name is big enough and people are told they want it, they'll buy it.