Writing for publication on the World Wide Web is much different than writing the traditional article for a print publication. In classrooms all across the world, students are taught to structure their non-fiction content by presenting an organized series of facts that culminate in a meaningful conclusion. This is referred to as the "pyramid" style of writing, in which the top of the pyramid represents the conclusion. In contrast, effective web-oriented articles use the "inverted pyramid."
The "inverted pyramid" writing style presents the conclusion first, then provides the supporting details. This makes web-oriented articles more akin to the news articles that you might see in USA Today than the longer, more detailed articles that you might find in a magazine like Time.
As with newspaper articles, readers of a web-based article may stop reading at any time. The inverted pyramid ensures that most readers will receive the most pertinent information from the article, even if they don't read the entire thing.
Studies have shown that many readers won't scroll down to read the rest of an article that is longer than can be conveniently displayed on the screen. This provides a further indication that the inverted pyramid style can be effective in communicating ideas to users.
Additionally, it highlights the fact that web-based articles will tend to be shorter than their printed counterparts. A typical web-based article may run between 300 and 700 words. A longer article would probably be divided into multiple articles, perhaps with hyperlinks connecting the individual articles.