1. You just want to have a preview
2. You have a fast connection and you don't want to wait for the download / you just want to watch it once
3. You just want to click and watch
p2p bit torrent streaming (built into browsers) would solve this. Hopefully this technology becomes more mainstream and then Cuban's point would be less valid!
I saw this one p2p streaming client on TC called rayv
1. You just want to have a preview 2. You have a fast connection and you don't want to wait for the download / you just want to watch it once 3. You just want to click and watch