So Google released a pretty cool interactive infographic "how search works"
How Search Works - The Story ? Inside Search ? Google
It's all basic stuff we as internet marketers know inside and out, but one thing I thought was really interesting are the "Live Spam Screenshots". You have to scroll down 9/10ths of the way and look for the "See what we've removed lately" link. It warns you that the results are generated live and are not moderated. All these pages are being marked as "pure spam", by monitoring the sites that pop up here, and looking for common factors you should be able to gain some insight into the spam filters and whatnot.
These sites are very obviously spammy so we're not going to learn anything profound, but I still think this is pretty interesting.
The next link under that "See Actions Taken Over Time" might be useful too.
By looking for spikes in certain types of "spam removal" you might be able to better identify why your site takes a hit.
How Search Works - The Story ? Inside Search ? Google
It's all basic stuff we as internet marketers know inside and out, but one thing I thought was really interesting are the "Live Spam Screenshots". You have to scroll down 9/10ths of the way and look for the "See what we've removed lately" link. It warns you that the results are generated live and are not moderated. All these pages are being marked as "pure spam", by monitoring the sites that pop up here, and looking for common factors you should be able to gain some insight into the spam filters and whatnot.


These sites are very obviously spammy so we're not going to learn anything profound, but I still think this is pretty interesting.
The next link under that "See Actions Taken Over Time" might be useful too.

By looking for spikes in certain types of "spam removal" you might be able to better identify why your site takes a hit.