Maybe I'm a numpty, but when I post something on the classiefieds and want to link to it from another site (like facebook for example) I do not get a "unique" link for my post. This means that even if I post the URL for the classifieds, my friends need to "hunt" for the post I'm referencing.
An idea would be to include the unique id for each post in the URL so we can link to it directly.