Does duplicate content penalize the whole site or just the pages affected?

[bjs2010]

I am trying to assess the impact of duplicate content on our e-commerce site and I need to know if the duplicate content is affecting only the pages that contain the dupe content or does it affect the whole site?

In Google that is. But of course. Lol

[bjs2010]

Thanks Tom.... Very valuable info.

A bit of background: we are running an e-commerce site - so I'm dealing with various forms of dupe content:

1. Descriptions that are copy pasted from manufacturers - e.g, replicas elsewhere - we are addressing this by writing our own content.
2. Dupe content between pages due to the products only change in colour or size - I am going to make these configurable products, so group them into one page.
3. URL params - this is a nightmare! Basically faceted navigation that is causing the same page to show very near similar content under different URL's.

Anyway, slowly fixing these - just seems like Google is painfully slow to respond to our work on improving things. Hence the question...

[TomRayner]

Hi there

In theory, the penalty can be either site-wide or page specific.  The majority of the time I've site-wide penalties.

A good way to check is to run your analytics data using the Panguin Tool - which will tell you if traffic drops have coincided with major algorithmic updates.

Similarly, the Chartelligence Chrome Extension allows you to measure traffic for your landing pages in Analytics.  Log into analytics, look at the landing page you wish to test and then activate the extension.  It will show you algorithm updates on your timeline, so any drop that coincides with an update may suggest that the particular page in question has been penalised.

Hope this helps.