Updated: May 3, 2011
As promised (…a little later than I first said, sorry), here’s an overview of what Google penalized sites for in their Farmer (a.k.a. Panda) update. It’s called ‘Farmer’ because many of the sites penalized were what many consider to be ‘content farms.’
Specifically and technically speaking, this particular update was algorithmic rather than manual in nature. All told, it affected over 12% of search queries in the U.S.
That adds up to some pretty significant numbers so therefore, it’s logical to see how more than just ‘content farm’ type sites were affected…many sites with good, high-quality sites were affected to. Many forums back this up as some sites say they lost as much as 50% of their U.S. based traffic from Google.
So what exactly were the issues surrounding Google’s Panda update and how do they affect my site?
While many of these affected sites claim they generated 100% original content, a deeper examination yielded of some of the example sites shown on forums and articles weren’t quite 100% original.
Specifically, sites affected by the update included one or more of the following 7 criteria:
(There were many more actually but these were the 7 most common)
1. Incorrectly or failing to use a canonical tag – especially common among e-commerce sites as Google would index two identical URLs
2. Excessive use of RSS feeds
3. Not providing unique content – as decided by Google. Essentially, they decide if your site is ‘authoritative’ enough and if they trust it
4. Optimizing for search engines rather than your audience
5. Using boilerplates too much and across too many pages
6. Having too many ads ‘above the fold’
7. Any site previously blocked manually by Google Chrome Personal
It’s safe to say sites undeserving of these kinds of penalties got caught in the cross-fire…Google even setup a Webmaster forum on the topic and has even admitted that it’s possible considering the fact this update was algorithmic rather than manual in nature.
Google says in reply to questions on its forum that since the Panda update was completely algorithmic in nature, Google cannot make any individual exceptions.
So basically what they’re saying is tough luck, too bad or whatever euphemism you can come up with to describe the situation. 
Considering this fact, it won’t do you much good to appeal to Google but if you find other, non-content related issues, then we suggest (…and our friends at Search Engine News do too) you contact Google about those issues.
To address these problems, we want you to remember this one important axiom – content is king!
It’s likely there are specific pages in your site that’s causing you to lose traffic. Isolate those pages and see if they fit any of the 7 criteria mentioned above. Either way, you should ensure those pages have 100% unique content.
If you’re an e-commerce site, generate product descriptions starting with your big products and working your way down. Not only does this prevent negative impacts from these updates, it will position your site for better long-term rankings.