This is a fascinating research project that's long overdue. According to a study conducted by a physics researcher at Notre Dame, an online news story will be barely read by anyone 36 hours after it was first posted. The PhysicsWeb article (thanks digg) says that "the short life of a news item -- combined with random visiting patterns of readers -- implies that people could miss a significant fraction of news by not visiting the portal when a new document is first displayed." Rocket scientists can download the full research here (PDF)
While I don't doubt the research (I nearly failed higher math), somehow I don't believe it takes the blogosphere fully into account. Blogs do a marvelous job of keeping a story alive for more than 36 hours. I'd love to see someone build on this with blog data.
Regardless, the Notre Dame research has implications for PR. As more people get their news online rather than off, teams need to strategize how they time key news announcements to capitalize on the 36 hours. Working with bloggers can keep the momentum going. In fact, a couple of years ago Mary Meeker covered this in some detail and I offered some PR context.
When I managed media relations campaigns, I used to suggest staggering big news over weeks - kind of like running a marathon. Now, with online news dominating, it might be better to get a bunch of quick hits in succession over a few days in a sprint-like fashion (for those who have this luxury) and then build momentum in the blogosphere.
