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I think navigation probably plays a large part, as well as website structure. If you have clear navigation with obvious subcategories you are more likely to get these pages as sitelinks. I have seen sites with no clear structure in the navigation have some strange pages picked for sitelinks - the pages were quite deep ones which kinda rules out PR or page strength. I also know that Google needs to determine that these results will be useful to a users query, so that fits in there somehow.

I believe that these will be valuable links.  I would go after them and that job would be priority on my list.

Thanks. I am trying to get the client to do this...Hopefully that will happen soon. We are also adding a live chat capability.