I've seen this once or twice now on at least two separate forums where once you post a thread the pr is automatically set to pr1 or pr2. The structure is domain/showthread.php?t=463200, and all new threads will have at least pr1. \ The pr of showthread.php in one case is pr2. How this is possible and is there a way to benefit from this observation?
THats not why, there is actually a structural reason which has been explained before. I have been struggling to find the thread though. I will post it if I can find it.
I've explained this before, the Google Toolbar (or atleast the non-beta one) trims everying after the ? before sending the PR request. It doesn't actually return the PR for /showthread.php?t=463200, it returns the PR for /showthread.php?.
Thinking about it, I probably posted it on another forum. For anyone who wants to confirm this, it's possible to do so by monitoring the Google Toolbar with a TCP/IP sniffer, requesting two pages e.g. showthread.php?t=1, and showthread.php?t=2 and monitoring the HTTP request sent out by the toolbar in each case. Even though they are two different URLs, you should see by the HTTP request sent out by the toolbar is identical in both cases.
If this is the case, all big stores which display products with querystring gets same PR value for all of their pages. Now a days, search engines r becoming smarter with dynamic sites. So it should not be the case in future.