A common misconception within the online community is that there are “penalties” for having duplicate content on your website. Many webmasters tend to get very antsy if they think the folks at Google et al are going to put them in “search engine jail” for having duplicates of this and duplicates of that on their website. In actuality, omission or de-ranking is reserved for only the most blatant offenders.
If your intention is to deliberately steal content from another website or spam your page’s content with keywords with the goal of ranking higher, then you should probably fear Google’s wrath. However, if some pages simply look very similar or are just duplicated because of a stubborn CMS, the worst that will happen is that one of these pages will simply be filtered out and demoted to the supplemental index. The best way around this is to either employ the proper redirects (a topic I discussed in my last blog post) or to make all pages on the site as distinct as possible.
Barring the iron fist of the search engines, it is still good practice to avoid duplicate content for the sake of your users. The more unique content on a website, the wider the reach you will have in the search engines and the better experience you will provide for your users.
Business owners will often purchase multiple domains to take advantage of all of the keyword potential that is to be had. For example, a webmaster that sells horse shoes online (I’m sure there are some) could own www.horseshoes.com, www.Ilovehorses.com and www.mykingdomforahorse.com. In this example, there are different reasons that this webmaster/business owner owns these different URLs.
The first reason could be that they all represent completely different business entities and/or types of websites and the content on each one is distinctly different from the other one. The person that owns and/or operates these websites has no intention of ever combining or redirecting them anywhere else. They are all websites with completely unique objectives that just happen to have something to do with horses.
The second reason (and usually the most common) is that all of these websites have the same or similar content and all share the same purpose; to sell this business’s horseshoes online. The problems that can incur if not handled correctly is content filtering or, even worse, duplicate content penalties in the search engines. To avoid this, one can employ certain strategies.
Firstly, you can identify which domain you prefer to use as the main domain and simply redirect the other two URLs to it with a 301 redirect. The second and probably the least practical solution is to keep them all separate, but make sure there is absolutely no content overlap. Another scenario would be to use the rel=”canonical” tag which (as of December 15th, 2009) you can use across multiple websites. While the rel=”canonical” link element is seen as a hint and not an absolute directive, Google says that they do try to follow it where possible. This tag lets you set the preferred version of a domain with highly similar content and is used in the section of all non-canonical versions of the site.
Too many outbound links on a website can deplete a site’s own PageRank (the importance Google assigns to a page based on an automatic calculation that factors in the link structure of the web and many other variables). However, this may be more of a relative than an absolute statement; there are ways to externally link to relevant websites without reducing the importance of your own website.
In its simplest form, PageRank can be explained with this formula:
PR(A)= PR(B) + PR(C) + PR(D)
From the formula above, the sum of the PageRank of pages B, C and D is awarded to page A because all of their links are pointing to A. Basically, pages B, C and D are passing on some of their own “link juice” to Page A.
PageRank is assigned on a page by page basis in that the more outbound links one has on a particular page, the PageRank of the page itself is affected. An intelligent strategy is to create a page on the site that includes a collection of links to websites that your users will find helpful. This is a good idea as externally linking from an internal page on your site as opposed to the homepage will not have that much of an affect on the site as a whole. The homepage typically has the highest PageRank by virtue of the links pointing to it. That PageRank from the homepage flows to the internal pages on the site. So, to keep that healthy internal link structure intact, we’d essentially want to have outbound links coming from a lower level page.
However, all of this can be completely avoided with the nofollow attribute. A few years ago, Google put into action the nofollow attribute so webmasters could link to other websites without losing their own “link juice”. This is useful if a webmaster wants to provide links to other quality websites for their users and not lose their own PageRank status.