XML Sitemap Indexation Rate Decrease

[RobbieWilliams]

On September 28th, 2013 I saw my indexation rate decrease on my XML sitemap that I've submitted through GWT. I've since scraped my sitemap and removed all 404, 400 errors (which only made up ~5% of the entire sitemap).

Any idea why Google randomly started indexing less of my XML sitemap on that date? I updated my sitemap 2 week before that date and had an indexation rate of ~85% - no I'm below 35%.

Thoughts, idea, experiences?

Thanks!

[DanDeceuster]

Every time I have seen this happen it is due to duplicate content across various URL's or very thin content. Google doesn't tend to want to keep an index of the same page many times or many pages with little to nothing on them. If you didn't have duplicate or thin content problems and have cleaned up your error producing URL's then I'm not sure what to tell you. Someone will probably have to get into your GWT account to diagnose from there.

[RobbieWilliams]

This post is deleted!