Our sitemap contains roughly 750,000 paths to discrete pages and only around 30 thousand are reported by google as being indexed.  I am trying to figure out why this is. The content of our pages is not what I understand to be thin; they contain a large amount of unique text, images and links, so i'm hoping this is not a duplicate question. The urls are broken up into several xml files of 30 to 50k urls each, and our robots.txt points to a sitemap that is an index of these files.           I understand that this is a broad question, so I have a few theories:   Theory 1:  Our site is viewed as a link farm: our overall site contains about 5 million pages, 99% of which contain links to 3 domains, www.outbound1.com, www.outbound2.com and our site itself (example.com).  Some of our pages have 500+ links or more.  My assumption is that google views this negatively and does not index our pages accordingly.Theory 2: Google only indexes pages that others have searched for.  Much of our data is incredibly specific, we have pages unique to an individual, or a page showing all content related to a unique topic.  My assumption is that users are simply not visiting a majority of our pages and that this relates directly to our low indexing.I'm hoping someone can confirm or dismiss my assumptions and maybe fill me in on something obvious I'm missing.
Google is reporting only 5% of our site's pages as indexed after one year
google;indexing
The number of unique pages that Google is willing to index on any particular site is tied to the reputation of that site.   When you start a brand new site, Google may only be willing to index 1,000 pages.  A year in, Google is willing to index near 40,000 pages on your site.  That is an indication that your site's reputation has grown with Google within your first year.Even for a very high quality site, it may end up taking two or three years to get enough reputation to get Google to index 3/4 of a million pages.  I don't think that there is an indication of any sort of problem other than that your site is still not very old.There are two things that you can do:Improve your site's reputationGoogle still uses back links as the primary indication of reputation.   If you want to work on increasing the reputation of your site, make sure you are taking advantage of every possible inbound link.   It has long been blackhat to spam links to your site.  Recently, Google has even cracked down on link building.   If you do decide to do link building, make sure that you do so from topical sites, with non-keyword rich anchor text, and in a way that doesn't look unnatural to users.Make sure your best content gets indexedGoogle may not index everything on your site, but you can make sure that it indexes the best content on your site.  Link prominently and often to your top content.   Your home page likely has the most link juice of any page on your site.   Use it well.   Any content you feature on the homepage with a link, will get indexed easily.   From those content pages, link to your second tier.  From their link to a third tier.  Anything more than three clicks from the home page is not very likely to be indexed.