Affiliate link giving duplicate content penalty?

[ep90]

Our website has suffered a big drop in google rankings and I think this may be due to an unintentional duplicate content penalty. We redirect all out outgoing affiliate links through a page called product.asp. We have disallowed this page in robots.txt and added:

<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">

to the page header.

All this action however has not stopped google indexing these pages. The problem is google calls the page
www. mysite.com/product.asp?pid=12345abc but the actual page content is the data from the merchant site. I believe google thinks this content is hosted on our site therefore giving us a duplicate penalty.

Has anyone experienced anything like this before? Any tips on recovering from this situation?

[fizzbird]

I believe google thinks this content is hosted on our site therefore giving us a duplicate penalty.

Wouldn't the duplicate content penalty just affect the page in question? If so, then why is it being indexed?

[ep90]

Wouldn't the duplicate content penalty just affect the page in question? If so, then why is it being indexed?

I'm not sure how the google penalty system works in this situation?

If I search google for site:mysite.com product.asp there are thousands of pages listed, but the actual title and content is for the merchant site. So they are being indexed for some reason. I did have

Disallow: product.asp

in robots.txt but have since changed this to

Disallow: /product.asp

after validating robots.txt with an online checker. What is weird though is google webmaster tools is showing product.asp under "urls restricted by robots.txt" but at the same time has indexed the pages?

[fizzbird]

I'm not sure how the google penalty system works in this situation?

If I search google for site:mysite.com product.asp there are thousands of pages listed, but the actual title and content is for the merchant site. So they are being indexed for some reason. I did have

Disallow: product.asp

in robots.txt but have since changed this to

Disallow: /product.asp

after validating robots.txt with an online checker. What is weird though is google webmaster tools is showing product.asp under "urls restricted by robots.txt" but at the same time has indexed the pages?

Odd indeed?
I don't think it's that uncommon for google to ignore the robots.txt although I' can see how this would be causing you a problem.
Sorry I can't offer anything constructive, it's beyond my level of understanding. Hopefully someone else will have the answer for you

[ChristopherB]

If you done this today or in the last week then google will still be showing your urls because they have already been indexed. - They don't just disappear in a heartbeat when you disallow a certain page from being indexed.

You can remove certain urls from within google webmasters tools, that would be my next step and make sure no other of these pages get indexed.