The List of N Things: Paul Graham nails the psychology of the list article and why it plays so well on the web – it guides us through the topic, and doesn’t force us to think too hard.
Structurally, the list of n things is a degenerate case of essay. An essay can go anywhere the writer wants. In a list of n things the writer agrees to constrain himself to a collection of points of roughly equal importance, and he tells the reader explicitly what they are.
Some of the work of reading an article is understanding its structure […] As well as being explicit, the structure is guaranteed to be of the simplest possible type: a few main points with few to no subordinate ones, and no particular connection between them.
I’ve talked about this before: The Psychology of the Bullet Point.
Bullet points signify a complete, contained, discrete thought. They encapsulate some nugget of information, separate from everything else. A bullet point tells us, “this piece of information is absorbable solely from the text in it,” and the text is usually short.