TheBigK - 6:18 pm on Dec 16, 2012 (gmt 0)

@Frost_Angel: Thanks. It does help me in my analysis and my ongoing observation of the situation.

@dilberry: I might be completely wrong and they might be completely right. It's just that I'm believing what I see in the stats - that my traffic dropped at the same time when the error count shot up. I'm not sure if that's a pure coincidence with something else that decided to rank our site lower. I do see several low quality websites outranking our pure, original content.

@sgt_kickaxe: In our case, all the bad URLs that returned 404 were phantom URLs. They got created in bulk because of some javascript error in Disqus plugin. Since our website is crawled every minute by Google, it indexted thousands of them on daily basis for about 6-7 days and then another wave of these URL discover tanked our traffic. In short, Google started discovering errors, from 1k to about 17k and then from 17k - 36k when our traffic dropped. The error count went up to 99k by the time I figured out what the problem was.

I fixed the problem by redirecting all the error URLs to correct URLs. I don't know if that was a right thing to do; because had I not done that, I'd still be sitting with ~90k errors, making Google think our site is still crappy and not improving our crawl rate.

I'll only know whether my solution worked if our traffic restores after the error count drops. I'll keep everyone updated.