Man am I sick of this issue. I personally think every website should have a 301 redirect (or something similar in effect) set up so that either the domain with or without the www is the primary. Why? I will tell you!
I have seen far to many prospects or forum members run into this as an issue. They are usually in a fantastically frantic state because of the loss of rankings or maybe never even getting them in the first place. I calmly tell them that one reason Google, Yahoo, etc could be demoting them is because of content duplication. They respond with the standard, “not me, nope, nope, nope! I have all original content and actually write my own articles too.” After explaining to them that the www in front of the domain can be recognized as a separate website as the one with, partially because of IBL’s (In Bound Links) from other websites telling the SE’s that these websites do exist, they start to listen.
Of course we all know and hope other websites will link to ours without us having to ask, but when they do link how do they do it? Do they use the www in the code or not. Most of the time I find they do, but all it really takes are a couple of links without the www to your most important domain for trouble to start to bubble.
On the flip side I have seen websites exist of years without them being effected what-so-ever. So when is it really a problem? I feel you need to have a substantial amount of solid PR websites linking with both methods to cause issues within the search engine(s).
Of course there is hope. Once your code is implemented it generally takes each engine an update or two to get things straightened out. Longer if you are switching totally from one domain to the other.
Implementing this code is very easy to do on Apache server environments, but gets more tricky on IIS. You can do a search on WebProWorld or Google for implementation tutorials and code.
Of course it is not just clients, but many very popular web properties do not actively use the 301 technique, but I must say over the past few years I am seeing more and more implement them, more than likely it is tied to more of them hiring SEO experts internally, agencies that do the work for them or outsource everything to a large SEO company.
When you find yourself linking to another website because you find it a resource, cool, whatevertry to use the www in front of the domain since it is the most common method.
Jaan Kanellis, is owner and operator of an independent SEO consulting company, www.KBKMarketing.com. Jaan Kanellis distributes his articles through the newly created SEO blog, www.JaanKanellis.com. Feel free to visit these websites and contact him if interested in his consulting services.
