E-Commerce Duplicate Content

[toddyC]

Hello all

We have an e-commerce website with approximately 3,000 products. Many of the products are displayed in multiple categories which in turn generates a different URL!

Accross the entire site I have noticed that the product pages are always outranked by competitors who have lower page authority, domain authority, total links etc etc.

I am convinced this is down to duplicate content issues. I understand there is no direct penalty but how would this affect our rankings? Is page rank split between all the duplicates, which in turn lowers it's ranking potential?

I have looked for a way to identify duplicate content using Google analytics but i've been unsuccessful. If the duplicate content is the issue and page rank is divided am i best using canonical or 301 redirects?

Sorry if this is an obvious question but If i'm correct we could see a huge improvement in rankings accross the board. Wow!

Cheers

Todd

[zen2seo]

When Google finds more than one document (ie URL) with the same content, it has to define which of them is the representative document of the cluster. In doing this it looks at inbound link metrics, essentially, plus date of the page, pagerank and other factors. In this decision, it can be wrong, indexing a page that can hurt you indexation (consider this situation: it indexes as representative document page 2 of a listing page in descending order: new items in this category end to be at page 2 or later and are less likely to be discovered).

The canonical tag can be a good solution, even if it is a hint and not a rule to Google...

[toddyC]

Great stuff thanks!...

[saibose]

SEOMOZ had an awesome whiteboard on this.

http://www.seomoz.org/blog/whiteboard-friday-faceted-navigation

Some more additional resources:

http://www.seomoz.org/ugc/dealing-with-faceted-navigation-a-case-study

Matt Cutts on faceted navigation:

http://www.stonetemple.com/articles/interview-matt-cutts-012510.shtml

Hope they help you

[toddyC]

Thanks again! Unfortunately our system was built in house from scratch with no consideration for duplicate content

To be honest the product pages that I'm worried about have very few or no inbound links so maybe this isn't such a huge issue.

I have picked up on the fact almost all our pages including the homepage work on www and non www so maybe creating a 301 redirect for these will help also.

I will test the conical tag on a range of pages and mointor the results, hopefully our rankings will increase and I can look at some kind of strategy to roll this out.

Cheers for the help!

[E-dreamz]

Google will select the most authortive aka whichever has the most links.

If you have a ton of inbound links I would recommend doing lots of research before inserting that tag. Find out which pages have the authority and don't throw it away.

This was a plague of eCommerce for years. Luckly most of the newest moden platfroms have caught up.

[baptisteplace]

The duplicate item pages will not be indexed but visited the google bot. He will consider this page to be the one linked in the canonical tag.

I hope you won't have to set the urls manually !

[toddyC]

Thanks for the quick response chaps! So if we have 9 duplicates for example will Google index all 9 pages or decide on 1 and never revisit the rest.

I couldn't see any duplicate URLs in the top content report.

We have over 3,000 products so it will be fun adding canonical tags to all the necessary pages

[baptisteplace]

Toddy,

For every product of your site, you should identify its main category (the one that will be indexed). When seeing a product with a different category url, use the rel=canonical tag to give google the good url. This works well with e-commerce site.

You may also apply this logic between categories, as some listing between two categories are sometimes very similar.

For more information about the rel=canonical tag, see these resources :

http://www.seomoz.org/blog/canonical-url-tag-the-most-important-advancement-in-seo-practices-since-sitemaps

http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=139394

[E-dreamz]

The only "penalty" is the fact you could potentially spread your link juice across those multiple pages. Example:

You have 104 links to the same product, but they are equally pointed a 4  unique URLs. Now you technically have 26 links on whatever page Google 'selects' as your authority page.

Your competition has 100 links to the same product which only has 1 page.

With that type of setup your competition is always going to have that authority page ranked abouve you.