I've only ever used the sticky feature for one site which I built on WP.com four or five years ago. The organization wanted an introduction on the blog page, similar to category descriptions. Without a widget area above the content area, the easiest solution was to use the sticky post function to display the intro info. We backdated the post to be the very first one so it wouldn't be prominent in the archives, published the post without a title so it wouldn't be linked from excerpts, and removed the read more link from the excerpt so it would appear as a simple intro rather than a post on the blog page (I believe it was just hidden with CSS). It wasn't a perfect solution, but it worked well at the time...