"Never underestimate the bandwidth of a station wagon full of tapes." -- Dennis Ritchie
I recently finished backing up all of my DVDs to image files on my home media server, which can hold no less than three terabytes of data. This took several weeks. Running
find . -type f | wc -l now tells me that I have 363 DVDs in my collection. Combined, these 363 discs take up two terabytes of space.
For perspective on that, let's say that you're an average American with a 10Mbps broadband connection. This means that under ideal circumstances you can download 4.5 gigabytes, or one average DVD, per hour. Downloading my entire DVD collection, allowing for no interruptions or slowdowns, would take over half a month!
It gets even better when you look at Blu-ray discs; at 50 gigabytes, those have five times the maximum capacity of DVDs. Downloading a single Blu-ray disc would take the average user over ten hours!
To top things off, let's imagine that Amazon offered Blu-ray downloads in the same way they do MP3 downloads. The average user's hard disk is probably about 300 gigabytes these days, so they could only own about five of these super-hi-def movies before running out of places to put them.
Of course, there's lots of services streaming 1080p video over the Internet now, and they don't buffer for hours before they start playing or fill up folks' hard disks. That's because the video bitrates, and consequently image quality, are horrifically low compared to a good Blu-ray.
Streaming video has its place, sure, but I won't be letting go of my shiny discs just yet. It's easier to get files that big by US Mail than by Verizon FiOS.