The funny thing about duplicate content is that you don't really have to have it for it to appear as if you do have it. But whether you have duplicate content on your site or not, to the search engines appearances are everything . The engines are pretty much just mindless bots that can't reason. They only see what is, or appears to be there and then do what the programmers have determined through the algorithm.

How you set up your internal linking structure plays a significant role in whether you set yourself up to appear if you have duplicate content on your site or not. Some things we do without thinking, setting ourselves up for problems ahead. With a little foresight and planning, you can prevent duplicate content issues that are a result of poor internal link development.

For example, we know that when we link to site.com/page1.html in one place but then link to www.site.com/page1.html in another, that we are really linking to the same page. But to the search engines, the www. can make a difference. They'll often look at those two links as links to two separate pages. And then analyze each page as if it is a duplicate of the other.

But there is something we can do with our internal linking to alleviate this kind of appearance of duplicate content.

Link to the www. version only

Tomorrow I'll provide information on how to set up your site so when someone types in yoursite.com they are automatically redirected to www.yoursite.com. It's a great permanent fix, but as a safety measure, I also recommend simply adjusting all your links internally to do the same.

In the image above you can see that the domain contains the www., but when you mouse over any of the navigation links, they point to pages without the www. Even if you have a permanent redirect in place, all the links on your site should point to the proper place. At the very least you're making the search engines and visitors NOT have to redirect. At best, should your redirects ever fail, or get deleted, your site will still be set up to handle everything properly.

Don't link to secure versions of non-secure pages

I already covered how to set up your shopping cart links in a previous post, but I'll go ahead and touch on it here again. People often make two mistakes:

1) They send visitors to secure pages as soon as someone adds a product, and/or
2) the site links link out of the secure area using secure URLs.

When setting up your shopping carts, make sure visitors don't enter the secure area until they are ready to check out. And when they do, make absolutely sure that any links back to the main site go to non-secure pages.

For the latter, one of the ways to prevent that is to use absolute URLs in your global navigation. Absolute URLs contain the full URL page: http://www.site.com/page.htm. When you use relative URLs, the link only contains the relevant information needed to get from point A to point B: /page.htm or ../page.htm. The rest of the information is assumed by the browser based on where the visitor is in the site. So if they are in the secure version of the site (https://), all relative links will tack on the https:// by default. To prevent this, absolute URLs are the only way to go.

And don't forget the items in your shopping cart. Products that link back to the product pages also need to use absolute URLs!

Link to the root, not home page file name

By nature, every site really has two (or more) home pages: www.yoursite.com and www.yoursite.com/index.htm will both take the visitors and the search engines the same content. There are two fixes for this. One is to create a permanent redirect which I'll discuss tomorrow. The other is to change all your "home page" links to point to www.site.com. If you use global includes for headers and footers, this is relatively easy. If not, then you might have to go in and change all your pages by hand. Either way, it's worth taking the time doing.

This article is part of a series on duplicate content. Follow the links below to read more:

1. Theories in Duplicate Content Penalties
2. How Poor Product Categorization Creates Duplicate Content and Frustrates Your Shoppers
3. Redirecting Alternate Domains to Prevent Duplicate Content
4. Preventing Secure & Non-Secure Site Duplication
5. Why Session ID's And Search Engines Don't Get Along (Hint: It's a Duplicate Content Thing)
6. What Does a Title Tag, Title Tag and Title Tag Have In Common?
7. How to Create Printer Friendly Pages Without Creating Duplicate Content
8. How to Use Your WWW. to Prevent Duplicate Content