Canonical Question

[Corpsemerch]

Our site has thousands of items, however using the old "Widgets" analogy we are unsure on how to implement the canonical tag, and if we need to at all.

At the moment our main product pages lists all different "widget" products on one page, however the user can visit other sub pages that filter out the different versions of the product.

I.e.  glass widgets  (20 products)
glass blue widgets (15 products)
glass red widgets (5 products)
etc....

I.e.  plastic widgets (70 products)
plastic blue widgets (50 products)
plastic red widgets (20 products)
etc....

As the sub pages are repeating products from the main widgets page we added the canonical tag on the sub pages to refer to the main widget page.  The thinking is that Google wont hit us with a penalty for duplicate content.

As such the subpages shouldnt rank very well but the main page  should gather any link juice from these subpages?

Typically once we  added the canonical tag it was coming up to the penguin update, lost a 20%-30% of our traffic and its difficult not to think it was the canonical tag dropping our subpages from the serps.

Im tempted to remove the tag and return to how the site used to be repeating products on subpages.. not in a seo way but to help visitors drill down to what they want quickly.

Any comments would be welcome..

[Corpsemerch]

Thanks, as i thought the issue is something that cannot be answered until its done.  I am going to leave the tag in for the moment as we are still ranking for keywords.

Will however watch traffic closely and compare over next to previous landing pages.

Thanks for the comment.

[Dr-Pete]

Technically, Google doesn't recommend the canonical tag in these situations, but it's a gray area. They do say that you can set a canonical to the "View All" version in paginated search results, and you've got something similar here - each sub-page is a sub-set of the full results.

Other options are to simply META NOINDEX the break-down pages or tell Google to ignore the parameters in GWT. Unfortunately, it really depends a lot on the situation and URL/crawl structure, so it's a bit hard to speak in generalities.

I'd be very surprised if this caused you any kind of Penguin problems. I've seen bad canonicalization cause problems in general, but it's probably just coincidental timing here. The biggest risk would be if you had direct traffic/links to the sub-pages. The canonical should pass most of the link-juice, but if a lot of people were running queries like "glass blue widgets" and "plastic red widgets" then canonicalizing those back up to the root page may have weakened your ranking ability.

It's a tough call - often, cleaning up these kinds of near-duplicate pages can be helpful, but it really depends a lot on your audiences and the nature of your traffic. Can you isolate the lost traffic? See if it was coming directly to these deeper pages or via long-tail keywords. If it was, it's very likely cutting off these pages caused some harm. If you've lost ranking on broad keywords or across all pages, then I suspect something else is going on.