What causes a story to propagate among mainstream media? Usually there is a combination of factors, but the main cause is it gets picked up by a wire service which other newspapers use to create the stories the propagate. This formation has shown to be the most useful due to the cost and profits of running a newspaper consisting of only custom content. Rather than self-produced content, one main service like AP runs a story and duplications are made from there.
For example, if we look at a news story such as:
Florida Democrats keeping their primary at January 29th despite threats from the party not to count their delegates. We see about 35 original stories on Google News, and 554 if we include the duplicates. We have a central source feeding the lesser sources. The propagation is mostly due to a centralized sources AP feeding stories from one source into multiple sources. The structure of the beast is such that news is centralized and duplicated, but the reasons for picking up the story for the wire is easily influenced. If the story isn't picked up, the success for that story to propagate is nearly nil.
Now, how does the evolution of blogosphere stories differ from this? What is the difference in the structure and propagation reasons. In the blogosphere a good portion of the content is either original or comes from traditional news sources (which in turn come from the wire services).
For example, the same story about Florida Democratic Party decision is picked up by the blog Pushing Rope, which references the blog The Buzz (run by a traditional newspaper) of Karen Thurman's response to the decision. As well as referencing the FDP's new website to try and make the national party give in, a Fox news article that says the DNC isn't, as well as a blog radio podcast about the story.
Blogs tend to echo the same story as well, though each with different input, and additional crosslinks. The stories aren't centralized and rather seem to form more of a mesh, and in different parts a tree. Such as the previous blog entry about breastfeeding on Facebook being carried through four different blogs each linking from one to the next.
Now, what causes the propagation of the blogs seems to be the real marked difference. Rather than having a single chance to set off a series of secondary pickups there seems to be a mesh of content. Rather than having the same story propagate out through all the blogs, stories tend to propagate through a sparse tree of blogs dedicated to the same sort of content. Certain blogs will link to other blogs and get a fairly broad listing of the story, though far from universal. And it all depends on how many people write about the story in question. Within the MSM paradigm, a single "picked up" event can make all the difference. Blogs amount to a decentralized specialized network for story propagation.
The decentralized structure has less ability to be managed or destroyed. For example if aliens destroyed the AP, the AP would be unable to report about it and a number of newspapers would be unable to carry the story. Bloggers, however, would be unaffected by the destruction of a large number of bloggers and blogs. The centralized structure for propagation allows for quick updates, for example if a story is several minutes old it is nearly impossible for any significant propagation among blogs to have occurred. Whereas MSM could already have achieved saturation. This MSM saturation could lead to the primary sourcing of the same story among many bloggers, fitting primarily into the centralized paradigm in such a situation.
Which provides better content? -- I would have to believe the blog content has typically been deemed at least interesting by multiple parties before the story appears, typically with some original content. And due to the specialization of the blogs themselves the content is more customized to the consumer.
Which is faster? -- Traditional media, is centralized and quick to respond to a story by creating thousands of locations for output for the identical story. It is doubtful that blogs could replace breaking news in any capacity.
Which is more robust? -- I would say blogging would be more robust simply because there is no head to cut off, nothing really to control.
Which is apt for tampering? -- If anybody could interject or prevent stories from being picked up within the centralized location then propagation of the story is nearly impossible. One could easily control the news with a centralized source, whereas a decentralized network would be nearly impossible to control. And nearly impossible to tamper with.
Which is biased? -- There is generally a concerted effort within MSM to be unbiased, though there is considerable problems with it, I daresay they should get the nod. They can actually prevent bias by being able to control the news, whereas many blogs are specifically biased towards one view or another. Though, they wear it on their sleeves... for example I am a godless, liberal, atheist, pro-choice, anti-death penalty, mythicist, in favor of universal health care... whereas Fox News is Fair and Balanced... they swear! Though there's a lot to the idea that if you know where somebody is coming from you can account for opinions. Very few people have a problem with Fox News having a bias, they strongly object to not admitting this bias.
Which is best? -- I don't know. Certainly there is a niche for story propagation here. Though, there may be different optimal propagation depending on the type of story. So far, it seems, that MSM is dying out or at least suffering at the hands of blogs. I'm obviously leaning towards blogging. Mainstream media has an advantage in that they can propagate information quickly, for breaking news important to everybody this is extremely useful. However, they never provide me with information about what's up in the atheist community, or what some particularly stupid creationist is doing this week.
Which provides better information? -- I don't know. The selection for the stories is not based on the truth content thereof, but the chance that the story is duplicated and blogged about for whatever reason. For example, there are a large number of people who actively blog about how vaccines cause autism, even though they don't, and never have. There is also a major difference between what MSM finds to be newsworthy vs. what users themselves find to be newsworthy. Which may cause a rather marked difference between information attained. A world affairs test might not be a proper metric as certainly MSM might do a better job at that than the number of atheism and science blogs I read. However, my religious and scientific knowledge compared to MSM users would easily be superior.
One primary difference between the two is the game theory strategy used. Mainstream media optimally provides the worst still important news available. The broadest and blandest, where the solution provided will still result in a net gain among all people. Mainstream media finds the best average appeal to a largest number of agents, whereas blogs can serve much more limited numbers of people with far more specialized content. So consumers have more control over the information they receive. So the fitness of a story with rapidly changing information is greater within the mainstream media, whereas a story about the closing of the Arecibo Observatory finds consumers more aptly and propagates better within a certain subsection of the blogosphere. Whereas the broad appeal of the story may be limited and thus isn't part of the best average solution, it could be part of a very specialized solution of astronomy or science blogs.