How do we decide which pages to index/de-index? Help for a 250k page site

[ggiaco-siftery]

At Siftery (siftery.com) we have about 250k pages, most of them reflected in our sitemap. Though after submitting a sitemap we started seeing an increase in the number of pages Google indexed, in the past few weeks progress has slowed to a crawl at about 80k pages, and in fact has been coming down very marginally.

Due to the nature of the site, a lot of the pages on the site likely look very similar to search engines. We've also broken down our sitemap into an index, so we know that most of the indexation problems are coming from a particular type of page (company profiles).

Given these facts below, what do you recommend we do? Should we de-index all of the pages that are not being picked up by the Google index (and are therefore likely seen as low quality)? There seems to be a school of thought that de-indexing "thin" pages improves the ranking potential of the indexed pages. We have plans for enriching and differentiating the pages that are being picked up as thin (Moz itself picks them up as 'duplicate' pages even though they're not.

Thanks for sharing your thoughts and experiences!

[julie-getonthemap]

I was advised to deindex pages that had not been visited in the recent past. I deindexed about 150 pages and had a nice bump in the SERPS. Previously I was #9 and I jumped to #4. I have about a hundred more thin pages I'm working on and #crossyourfingers maybe I'll be top three.