Breadcrumb trail resulting in duplicate urls

Question

In an e-commerce site I have products that can be under more than 1 category, this causes multiple urls for the same product, the reason being is that if a user clicks on category A then on product A the breadcrumb trail shows a link back to category A.

The only issue is, in order to ensure that the breadcrumb truly reflects the path the user has chosen I have included the category id in the link to the product, i.e:

/product?id=10&cat=5

...and because products can have more than one category there might be:

/product?id=10&cat=6

However, the usual url for a product would be:

/product?id=10

This obviously means I'm having more than 1 url for each product potentially.

Is there a better way to ensure the correct breadcrumb trail?

Or is this really not that much of an issue?!

Answer 1

This is a problem because it potentially will cause duplicate content issues with Google. But you can just use canonical URLs to indicate the one URL you want to represent that page. That easily solves the problem.

Answer 2

I would do something similar (as breadcrumbs are really only for the user not search) but i would store it in a session variable instead of in the URL.

Now i dont know what language you are in, but i use VB.NET so it's simply

session("category") = 6

then read it back in when loading the product page.