How serious is duplicate page content?

[devonkrusich]

We just launched our site on a new platform - Magento Enterprise.  We have a wholesale catalog and and retail catalog.  We have up to 3 domains pointing to each product.  We are getting tons of duplicate content errors.

What are the best practices for dealing with this?

Here is an example:

mysite.com/product.html

mysite.com/category/product.html

mysite.com/dynamic-url

[irvingw]

in this case simply canonical tag the less optimized pages to the main page you want to represent your site

this would be the representative URL most likely:

mysite.com/product.html

I would lose the .html extension too.