With all pages within that folder called
My understanding is that Google will class all those pages as the same page (http://example.com/topic/) and individual pages (the ?pid=13 bit will not be indexed)
Unlike your there is no page specification!
So basically, if it can't be indexed, then any attempt to SEO the pages would be a waste of time... I am correct with this do you think?
In fact the only time I have seen this before is if people are trying to fake page rank, as every varible page gets the TBPR of the directory (even though its now even indexed, let a lone cached).
What do you think? Is there much different between my clients site and your own Shaddows?