Have you ever wished you could have your oldest posts continually pushed back to the top of the stack, in order to highlight old articles from your archives? It’s not something I would do myself, but apparently there are some who would.
HackWordPress.com has a post on how to do just that, and an example scenario of why you would want to.
Personally, I don’t like the idea of mucking around with the time stamps like that, it’s…odd. What I would do instead, is have a section in my template that would pull older posts and display them. Maybe five random linked headlines that are older than 6 months? With the $wpdb class, you can work some WordPress magic and do whatever you want.
Though, as I said earlier, there are probably some people who would want to do what the plugin makes possible.