Bloggers know all about link propagation. Someone will write about something and a few other people will link to it, then it goes away, a week or so later a blogger with a bit bigger readership finds it, links to it, and suddenly people are talking about it everywhere. When that "blogger with a bit bigger readership" is a site like slashdot or BoingBoing it usually results in hundreds of other sites jumping on it to stay current. You'd be amazed at how many people run blogs that are just collections of posts from other sites. A lot of these sites are people who probably should have blogged about it before, maybe they even saw the link but didn't write about it until after someone else with some "cred" did.

The media is a lot like this. Not that this is news to anyone. A story will exist for a while, and perhaps a few outlets will cover it, but it's not until the big guns take note that everyone makes the mad rush to write about something. Blogging is the perfect example. It's been happening for years. It's been a big deal for years. A few people have noticed, but it's been largely ignored by big media. With the DNC giving credentials to bloggers, it's not something that can be ignored and suddenly the big media outlets are talking "blogs this" and "bloggers that." The trickle down is local media across the country is rushing out to write about bloggers in their neck of the woods. People who have been there for years, doing things for years, but it took national interest for local acceptance.