We can see the growth of systems using peer to peer principles. But there is an area where peer to peer is not (yet) widely used: web hosting.
Several projects are already launched, but there is no big solution which would permit users to use and to contribute to a peer to peer webhosting.
I don't mean not-open projects (like Google Web Hosting, which use Google resources, not users'), but open projects, where each user contribute to the hosting of the global web hosting by letting its resources (cpu, bandwidth) be available.
I can think of several assets of such systems:
So, why such a system is not yet widely used ?
I think that the "97.2%, plz seed!!" problem occurs because all users do not seed all the files. But if a system where all users equally contribute to all the content is built, this problem does not occur any more. Peer to peer storage systems (like Wuala) are reliable, thanks to that.
The problem of proprietary code is pertinent, as well of the fact that an user might not know which content (possibly "bad") he is hosting.
I add another problem: the latency which may be higher than with a dedicated server.
The confidentiality of code and data can be achieved by encryption. For example, with Wuala, all files are encrypted, and I think there is no known security breach in this system (but I might be wrong).
It's true that seeders would not have many benefits, or few. But it would prevent people from being dependent of web hosting companies. And such a decentralized way to host websites is closer of the original idea of the internet, I think.
This is what Freenet basically is,
Freenet is free software which lets you publish and obtain information on the Internet without fear of censorship. To achieve this freedom, the network is entirely decentralized and publishers and consumers of information are anonymous. Without anonymity there can never be true freedom of speech, and without decentralization the network will be vulnerable to attack.
[...]
Users contribute to the network by giving bandwidth and a portion of their hard drive (called the "data store") for storing files. Unlike other peer-to-peer file sharing networks, Freenet does not let the user control what is stored in the data store. Instead, files are kept or deleted depending on how popular they are, with the least popular being discarded to make way for newer or more popular content. Files in the data store are encrypted to reduce the likelihood of prosecution by persons wishing to censor Freenet content.
The biggest problem is that it's slow. Both in transfer speed and (mainly) latency.. Even if you can get lots of people with decent upload throughput, it'll still never be as quick a dedicated servers or two.. The speed is fine for what Freenet is (publishing data without fear of censorship), but not for hosting your website..
A bigger problem is the content has to be static files, which rules out it's use for a majority of high-traffic websites.. To serve dynamic data each peer would have to execute code (scary), and would probably have to retrieve data from a database (which would be another big delay, again because of the latency)
I think "cloud computing" is about as close to P2P web-hosting as we'll see for the time being..