At their core, most job boards are series of one-way communications: employer posts a job; job seeker responds to employer; employer does (or doesn’t) respond to job seeker. Each communication is distinct and separated by both time and method – some might even say fragmented.
Compare to a blog, social networking site, or Twitter: you send out a communication – and built into your communication are methods for readers to respond, as well as the expectation they will; readers DO respond; you respond back. In other words, a conversation (albeit on Twitter an abbreviated one).
For the sake of this post, I’m going to boil Web 2.0 down to this: facilitating conversations via the web. There’s much more, of course, but most revolves around making websites more interactive and involving – in other words, pulling users into the conversation.