I was in the pub the other evening, trying to explain the difference between Web 1.0 ["Dotcom"] vs Web 2.0 ["Blog and Social Media"] to a web neophyte friend of mine.
The short answer: "Dotcom was about 'taking'. Web 2.0 is about 'giving'."
Dotcom basically built glorified Yellow Pages. You go, you get the info you need, hopefully you buy something en route. The relationship between the user and the website is impersonal, not unlike the realtionship between the Yellow Pages and its readers. They show, you select. They give, you take.
The architecture of Web 2.0, however, is about people giving away their stuff i.e. "sharing". Whether its a well-written blog post, or photos uploaded onto Flickr, or videos uploaded onto YouTube, the act of you giving is every bit as important as people other people receiving. This is why the number of blog readers isn't that much larger than the number of blog writers. Writing is as important as reading. Giving is as important as taking.
Suddenly for the first time in history, the world's most powerful form of media is about giving, not taking. The implications are vast.
This explains why Madison Avenue has had such a hard time getting their heds around blogs. Their culture is all about THEM giving, and nobody else taking i.e. producing a one-way exchange of information. People ['The Consumers"!] are only invited to "take". They're not interested in the reader being able to give back. "Giving" is only allowed by a bunch of pre-selected professionals, who are on their payroll, beholden to their rules, who they deem worthy to stay on message. Amateurs need not apply.
Giving vs. Taking. Exactly.
I was a dotcommer way back then, and used to giddily consume everything about everything related to Web 1.0 - these days, I'm so busy 'giving' (apparently) that i didn't even know what 2.0 meant, till now. Does that make me a neophyte?
updated to add this from gapingvoid.com, which has a lot of resonance, and might better describe web2.0
I'll also add that my mantra during the nineties dotcom era was 'user-created-content' - that seems to have panned out.