Do sitemaps kill sites? or is it something else.... ;)

I don't think that it is the use of Google sitemaps that hurts sites so badly. Many of the sites that I've seen talking about being reduced are in the mega-numbers... ok, more than 100 pages and usually MUCH more.

One site that I worked on a few months back had nearly 300,000 pages indexed in Google until I made some changes to the scripting. When the site: command returned 3,000 pages, the site owner flipped!

What I was doing to the site was setting up 'proper' 404 redirects instead of the 'hosting Control Panel' variety that redirects to the homepage and returns an HTTP Status code of 200 (Found).

What had happened was they lost all of the OLD URLs that weren't being used anymore. Once Google crawled the site and picked up the bad URLs (some were REAL badly broken), it kept returning over time. Two years later and 300,000 pages strong, this website finally 'confessed' to Google that most of the indexed pages were actually no longer on the server.

Enough history... When you setup an account at Google Sitemaps, they require you to 'fix' your 404's that report as a 200 (Found). Once they spider their old cached URLs, they realize that many of your pages are no longer around and drop them from their index.

In the case of my client, their ranks for current pages soared after this. It seems they may have also been hit with dupe content penalties for having 297,000 copies of their homepage!

This may not be the case for all pages dropped from the index, but it explains why it happens shortly after people sign up (and fix their 404's).

 

You are 100% right about this.

 

I've not had success with a Google sitemap either, but there must be some circumstances where it makes sense, no?

 

I went from 1680 index pages to having only 1, my top level url. I did nothing new besides submit a site map, I'm hoping they've just 'reset' me while they index my site as there were quite a few 404's.