Canonical URLs in an eCommerce site

[Gabriele_Layoutweb]

We have a website with 4 product categories (1. ice cream parlors, 2. frozen yogurt shops etc.).

A few sub-categories (e.g. toppings, smoothies etc.) and the products contained in those are available in more than one product category (e.g. the smoothies are available in the "ice cream parlors" category, but also in the "frozen yogurt shops" category).

My question:

Unfortunately the website has been designed in a way that if a subcategory (e.g. smoothies) is available in more than 1 category, then itself (the subcategory page) + all its product pages will be automatically visible under various different urls.

So now I have several urls for one and the same product:

www.example.com/strawberry-smoothie|SMOOTHIES|FROZEN-YOGURT-SHOPS-391-2-5

and

http://www.example.com/strawberry-smoothie|SMOOTHIES|ICE-CREAM-PARLORS-391-1-5

And also several ones for one and the same sub-category (they all include exactly the same set of products):

http://www.example.com/SMOOTHIES-1-12-0-4 (the smoothies contained in the ice cream parlors category)

http://www.example.com/SMOOTHIES-2-12-0-4 (the same smoothies, contained in the frozen yogurt shops category)

This is happening with around 100 pages.

I would add canonical tags to the duplicates, but I'm afraid that by doing so, the category (frozen yogurt shops) that contains several non-canonical sub-categories (smoothies, toppings etc.) , might not show up anymore in search results or become irrelevant for Google when searching for example for "products for frozen yoghurt shops". Do you know if this would be actually the case?

I hope I explained it well..

[Gabriele_Layoutweb]

Thanks a lot Anthony. Unfortunately the problem cannot be fixed at programming level so I'll try the "solution" with the canonical tags.

Cheers!

[anthonydnelson]

You are on the right path and realize you have a problem.

My #1 suggestion would be to fix this at a programming/development level to prevent this from happening. Canonical tags can be used to help/fix the problem, but they are more of a suggestion to the search engines as opposed to a 100% perfect fix.

If you can't eliminate the problem, have no fear using the canonical tags. Each category, subcategory and product should have their own canonical URL and the duplicates can canonicalize back to them.

[joseph.chambers]

Why don't you try to measure the impact one maybe 4 or 5 of the pages?