goodroi - 11:50 pm on Dec 19, 2009 (gmt 0)

Welcome to WebmasterWorld!

The thing you are doing wrong is thinking that the site: search on Google is highly accurate on large website - it is not. When Google says that it is showing results 1-10 of 174,000 it is actually guessing that there are 174,000 pages. You should rely more on the numbers provided in Google Webmaster Central than the site:.

If you a million pages it is highly unlikely that Google will index all of the pages. To index a page Google needs to deem that the page is useful & unique. When you have a million pages there are bound to be some duplicate or near duplicate pages. That is why most large websites don't have 100% of their pages indexed.

Congrats on getting over 100,000 pages indexed! Hopefully they are driving traffic that is converting for you.