Formally, this is done through an Inverted Pyramid style of news story writing - the most important information is communicated first, and the further into the story you go the less important the information is. In theory (and like anything, in practice things like personal experience and bias come into play) this means the story can be ended at any point and the most important news will be conveyed.
Where the story ends depends on News Hole (also what a lot of bloggers probably call MSM journos). This is the amount of space that needs to be / can be filled with news. The beauty of the internet is that it removes many of the factors that traditionally limit newshole, primarily the amount of space that can be supported by advertising.
And ultimately, it's this final point which may address the '3 key parts' identified in this article. When space is abundant, that information can be shared. And since it's often easier to write a longer article than a shorter one, in many cases the information discussed exists in early drafts and is later cut for space, meaning a lack of cutting provides extra information while actually saving time.
Don't get me started on the Janus view of the press, and how it will influence online media, however.
Credentials - Australian Press Council Prize Winner 2000; University of Queensland Journalism Prize Winner 2002. Google or Wikipedia key terms to find links to more detailed papers.