The information flows online are almost inherently chaotic, but let me try to boil down the swirl of information into three types. This classification will play off the familiar notion of peer-to-peer networks – P2P – in which (usually) widely dispersed ad hoc networks contributes bandwidth to meet computing needs.
• People-to-people – the ocean of emails, IMs, and text-messages that flow around the globe daily. Some of this is just chatter, but a lot of these emails are information-exchanges that matter a lot to people doing the chatting.
• People-to-amateurs – Harvard’s Law School’s Terry Fisher has talked about the revival of amateurism due to the internet. Shockingly enough, people without credentials and with interest in a particular topic can make their knowledge available – usually for free – over the internet. The quality of the offerings of amateurs often rivals that of experts.
• People-to-experts – people with formal training – anyone from doctors to mechanics – can and do offer their expertise to the world online. Again, this is often for free. They do this for free because it brings them reputational benefits.
Excerpt from What does user behavior tell us about the right way to reach people?, (pdf) remarks from John B. Horrigan on behalf of the Pew Internet & American Life Project.