The more I blog, the more I think about the length of blog posts. I often wonder whether it's better to write lots of short blog posts, or fewer longer ones. (And this question is not related to SEO. I'm thinking more about the effect of blog post length on bloggers' writing style and skill.)
I suppose the blogging medium itself lends itself to short posts. You can make a strong point, then quickly move on. And if you want to communicate a more comprehensive argument or series of points you can do that simply by linking to other blog posts or articles in the one post. Again your post will be short.
While using this technique is useful, I don't think you should overdo it. If you do, you can start to lose the facility to communicate your own thoughts thoroughly and completely. If a blogger tries to write a book, for instance, he won't have the luxury of linking out all the time. He has to include all the information actually within the text he's writing.
That's why making a point of occasionally writing longer posts, without linking out at all, is a good idea. You should also write articles of at least 500 words and submit them to directories. That's a good way to increase your focus and follow through. It's also great for SEO, of course.