If I write a thousand word essay on why CITIZEN KANE was an important, pivotal, but largely unwatchable film - very few people are going to read it to the end. And the style and the nature of my arguments will select out huge audiences. Those who remain to link or discuss what I've written will be of a pretty narrow group.
But if I just post "Top 10 Important Films I Can't Stand to Watch" and include CITIZEN KANE, it invites any number of conversations at various levels-of-depth. The potential audience is far, far larger and the territory open to discussion is vast.
At least two critics I respect, Merlin Mann and Paul Graham, have talked about this. My theory is much simpler: list posts tend to have good titles.
When you’re browsing a feed reader, you’re more likely to read an article called “10 Ways That Foo” than an article whose name is a complicated pun between its subject and the author’s favorite obscure novel.
People like getting information fed to them in lists.