Robert_Charlton - 7:46 am on Jul 2, 2010 (gmt 0)
Moreover As Robert mentioned if we put those listings in noindex then we can put their links in nofollow. Right?
curioustoddler - I wasn't suggesting noindex,follow for your situation... I was responding specifically to Frank_Rizzo's question.
With regard to your situation, when you say this...
Moreover these pages are so many in numbers that they exhaust all quota from gbot and our other important pages are left behind.
...it makes me think that this is a structural problem...
What you need to do is to make sure your pages get the most internal PageRank distribution and are crawled before the other listings are crawled. Most important here is your internal navigation. As tedster suggested earlier, you want your "core" city pages to be higher up in the nav structure than the ever-changing listings pages... and you may also want your own listings to be higher up in the nav structure than other agents' listings.
But if all listings are linked from the same page, then the rel="nofollow" on the links to the other agents would have the same effect as leaving those links as dofollows.
You need to set up the nav structure so that the other agents' listings aren't siphoning off PageRank (and distracting Googlebot) from the pages that you do want Google to spider, index, and rank.
That's not the same as keeping them out of the index or preventing them from getting spidered.
It is about creating a nav structure where Google sees your main pages and your listings on pages higher up in the nav structure, before the remaining PageRank is split among all the other listing pages.