To demonstrate the rise of user-generated content, Ms. Huffington said that more video was uploaded to YouTube in the last two months than if the major networks had created original content every minute of every day since 1948. She urged advertisers and media outlets to recognize that the abundance of user-generated content means content organizations need to step out of the center of the news universe and invite users into the news-gathering process — a model her own site, the Huffington Post, has grown up on. "

But before the progressive media establishment gets too cocky about its role, there are still major weaknesses and some dark clouds on the horizon. Clark and Van Slyke don't sidestep the obstacles, spending the better half of the book weaving the challenges of the future with the success stories and promoting models of social networking and collaboration they feel can increase the progressive media's new-found influence."

"Seth Godin uses a bit of biology to talk about viral growth today. There's some math behind it, so it can be measured (metrics!), but the bottom line is that a very small number of people with a high propensity to share easily trumps a very large number of people with a modest propensity to share.

In my view, the goal is to become remarkable. Literally remarkable, in the sense that people remark about your stuff. When you're remarkable, not only do you know it, your boss knows it. And there's hardly a need for metrics."

In the book, we define four areas for progressive media impact: buzz, credibility, influence + engagement.