HD is still much for the Internet, at least in the states. Even Microsoft's HD downloads for the Xbox are relatively low bit rates compared to cable. Even those with 15Mbps connection have a hard time utilizing their potential because few other hosts can match their speed and considering how rare 15Mbps connections are in people's homes, I would hate to see how saturated the Internet would get if they were more common and everyone started to download HD movies.
The real problem is that early adopters are the ones who would buy HD downloads and they are the same one who would potentially buy HD DVD or Blu-ray, both of which offer better pictures, sound and additional features.
The movie download business for the most part is behind almost 10 years compared to packaged media. Sure there is a market for downloadable movies, but even as popular as digital downloads are for music, it is still far from surpassing the sales of CDs.
How good could it be if it isn't HD?
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