Urgh. Another idea from the "bandwidth is free" brigade.
I guess for sharing low-volume personal stuff there's nothing wrong with the idea. It is still too much of a pain for people to set up a personal website. (Then again, most people don't have to these days with services like Flickr, Blogger and Facebook.)
If this ends up being used to host anything large/popular, though, then I think it's just going to increase the "bandwidth bubble" which is going to burst at some point. US internet users are complaining about 250GB usage caps being introduced (and places like UK/Australia have put up with much worse since day one) and I can't really blame the ISPs at this stage. (Not that the ISPs are perfect in every regard, but there's no such thing as a free lunch.)
Time was when half the bandwidth was paid for by whoever hosted the content. Now we're seeing more and more technologies move that cost on to the ISPs, as if it's free. (Obviously I'm massively simplifying the way the money is distributed here, but the fact remains that before people paid to host stuff and with P2P that money disappears while consumers still expect to pay the same as they always did for their internet access.)
As I say, for small-volume, personal stuff it's fine. But we've seen huge volume corporate loads use peer-to-peer models and I think that is, to use a UK phrase, taking the piss. For example, the BBC iPlayer tried to palm off its distribution costs on ISPs by making the thing distribute subscription TV via peer-to-peer. I find that ridiculous, and it was even more ridiculous that by default it would upload content 24/7 unless the user configured the background service. Another example that springs to mind is Konami distributing game updates for Metal Gear Solid 4 via bittorrent. If I am paying for content I expect not to pay to distribute that content, unless it's subsidised (which it never is).
(On the other hand, if something is given away free or very cheap then I don't mind P2P. As a good example, Nine Inch Nails released some records for sale online in MP3 and FLAC and they paid for the hosting, as they should have. But NIN also released some of the multi-track recordings in wav format for people to play around with for free and used P2P in that case. It was free so fair enough.)
Some of our upstreams may still be free for the time being but I can't see that lasting if more and more stuff moves over to P2P.
(On the flip-side, I suppose there is a positive effect to P2P as well in that it can get you some free local caching if the protocol is done right and the data is popular.)
EDIT:
I wonder how big the overlap is for people who:
- Use (or could put up with switching to) Opera.
- Need more than Flilckr/Blogger/Facebook/etc.
- Aren't technical enough to install Apache (or whatever).
This could be exciting for all five people in that group! 