Footer text and SEO

Hello,

We run a Online store with 17.000 indexed sites in Google. The domain is PR2 and 5 years old.
About three weeks ago, I did remove the footer text that includes about 100 words, and it was visible on each page.

After 2 - 3 days traffic was dramatically decreased, and did not recovered until today.
This was before the new Penguin update

Can be removing the footer text, the reason for loosing traffic this footer text?
Is footer text "duplicate content"?

Should I put it back?

Thanks to all for all advices

It really depends on the amount of unique, quality content your site has to determine whether the footer text would be classed as duplicate content in your case. Every site is bound to have some a little duplicate content (navigation, copyright info, widgets etc), but the ratio of this to actual unique content would determine whether or not it's harmful to your site.

The fact your traffic has recovered suggests to me that it was unrelated to the footer text.

Did you say that the traffic recovered today? I believe that Google ignores Boilerplate text. As long as your web pages have at least 40% unique content you should be o.k.

It may be the reason. If you feel footer text causes traffic drop include it and see. I have seen sites looses its rank when there is a change is website homepage. Same happened you i think.

Sorry for my wrong expression! The traffic is not recovered jet.
I did check our pages with copyscape and we do have in average 10 - 13% duplicate content on our pages

Some people claim that footer text no longer provides value. Perhaps the value has been diminished somewhat over the years but I still get a benefit from it in terms of rankings. As an owner of a web development company, whenever we launch a new website for a client with a lot of backlinks we typically get a big boost in rankings. The only reason to which I can attribute is the "Website Development by Companyname" link in the footer of each page on the website.