We recently had the opportunity to diagnose a pretty high level SEO problem on a website, and we'd like to explain it because it's a common problem that many people don't know about.
A larger jewelry product catalog site has a princess cut diamond ring categorized as a "Princess Cut Ring." Everything in that category naturally shows up on the Princess Cut Ring catalog page.
This makes total sense, however that same princess cut diamond ring is also inlaid with pave diamonds.
After looking at their Google Analytics they noticed many people were finding their princess cut/pave diamond rings after searching for "vintage rings" on Google. As a marketing strategy they added a vintage category to their catalog and copied many products from other categories into this new vintage category.
At this point, we should point out that right up until they started copying products, their website had absolutely zero duplicate content on it. The web programmers made sure to structure their site in such a way to prevent search engine problems.
However, without realizing it, creating this additional category for marketing suddenly introduced a new set of discrete URL with the same product information as found on the Princess Cut Ring page. This was a big oops!
Instead of seeing more "vintage ring" results in Google Analytics they were seeing less of both "vintage" keywords and "princess cut" keywords. They also started seeing duplicate page title and meta description errors in their Webmaster Tools account.
We consider this an "epic failure."
There are 2 possible solutions to this situation.
1. Use the <link rel=“canonical”> setting on the vintage pages.
2. Do a 301 redirect from the vintage pages to the associated Princess Cut Ring pages.
Here are the full explanations of those options:
Google crated a new link tag to allow for this exact situation. They understand that it's helpful for users to find the landing page for vintage rings and allow people to search like that. From their point of view, it's good customer service and good marketing.
The format of the HTML command to put on the "vintage" page is:
<link rel=“canonical” href=“http://domain.com/princess-cut-rings.htm”>
When Google sees the vintage diamond detail page it will ignore that page and instead pay attention to the original princess cut diamond ring page.
Everyone is happy because customer have multiple ways to search, Google is told to ignore duplicate content and the jewelry store will see better ranking again.
But there's a drawback to the rel="canonical" feature. Bing and Google admit that they only look at the feature as a "suggestion" and might not have the resources, or the desire, to follow through. That means all your hard work might still work against you.
Google admits that even though the rel="canonical" works, it's still better to use a 301 redirect for all pages and products that have duplicate content.
How this would work is you create your vintage diamond ring category, and the product page. You can also show all your product thumbnails, but when the user clicks on that "vintage princess cut ring," you need to either direct link, or 301 redirect, them back to the original Princess Cut Ring page that was originally created.
This technique forces the search engines to behave exactly the way you want them to behave. You have full control over your vintage landing page for SEO, and you give customers what they're looking for.
It took a little programming, but we chose to implement option #2 for the jeweler we were helping. On your website, you should make sure none of your products can be found on different URLs. Having them in different product categories is fine, just as long as the product detail page is always the same no matter the entry point.