Blogged thoughts, is our web blog. Expect views, opinion, rants and tirades about everything and anything 

I guess the title says it all. The topic is one of those that has been running for some time now, but as of yet is far from being resolved (conclusively anyhow) and since I’m going to be creating a new section on the akamarketing.com site soon I decided I would write about it, just to document my research of course, not to help you guys . The major issues surrounding this topic are outlined below.

More valuable keyword rich URLs?
It’s known that search engines provide at least a small relevancy boost for URLs which have keywords in them. MSN is in my experience particularly fond of keywords in URLs, I’m sure that Google and Yahoo do ‘take notice’ too. Many SEOs will for this reason place keywords in various sections of a URL to try and boost their rankings. Given the current topic at hand this brings us to the following question - Is a keyword in a sub domain more valuable (in terms of relevancy alone) than a keyword in a directory name?

Well as sub domains are generally considered as separate domains altogether by the search engines the keyword located in keyword.domain.com would I imagine be perceived as being more valuable than the keyword in domain.com/keyword. This is just my opinion of course, others are entitled to offer a different take on things. My thinking on this matter stems from the fact that traditionally sub domains have ‘housed’ very unique sections (like most regular domains themselves) of content and were not created arbitrarily when a need for a new section arised. Directories on the other hand get created without a second thought and are often created to organise content that isn’t really that unique when compared to the content in other directories on the same www space, thus directory names and the keywords in them have less ‘value’ in the eyes of the search engines.

What about link building issues?
Link building in the context of sub domains versus sub directories should I believe be thought of both in terms of actual getting links in the first place and then also in the relevancy of these links too. You will understand what I mean over the next two or three paragraphs.

Is link building easier for sub.domain.com or domain.com/sub? The ability to conduct an extensive link building campaign via directory submissions is a major advantage of using sub domains over sub directories for me and many other SEOs. The reason for this is that most directories will not accept a sites internal pages (or internal directories) for listing consideration if the main domain name is already listed but sub domains are generally considered to be a separate (but often related - so still some directories will not accept them) entity from the main site and thus getting links from directories for sub.domain.com will be much easier than getting links to domain.com/sub.

Depending on how you plan to get links for the new site section the directory element of this topic may force your hand one way or another. If you plan to get most of your links for the new site section from link exchanges, article marketing, press releases, link buying etc. then you could go either way without too much difficulty, but if your main efforts are going to be focused around a strong free & paid directory submission campaign well then if you are to avoid shooting yourself in the foot before you even start you really have to go with the sub domain option (assuming its compatible with the needs of a certain special someone).

As far as the relevancy of links are concerned, webmasters who are naturally linking into your new site (without being asked) section will often simply use the URL as the actual link text. Having a keyword.domain.com URL usually means that this happens more than if the URL was domain.com/keyword. The reason for this I’m not sure, but perhaps it’s because the sub domain looks neater and fits in better with existing links on the webmasters link page, anyhow this provides you with not just a standard issue link which simply points to your site but a keyword rich link which is much more valuable to you in terms of boosting your search engine rankings.

Is there any technical implications of using sub domains I should know?
From a technical point of view you must be aware of the fact that you can’t use relative URLs for linking between your main domain and your sub domain. This can be seen as a slight inconvenience but unless you absolutely need relative URLs at your disposal this shouldn’t effect your decision and besides your not going to want to do intensive crosslinking anyhow because this can raise a few suspicions with the Google anti spam team.

Should I choose sub domains or sub directories?
Above I’ve kind of come down in favour of sub domains slightly, no? Well yes to a large degree that’s true, only from a purely SEO perspective though, I’ve still to touch upon the most important entity (that aforementioned special someone) which you must factor in before making your decision however. That entity is of course the user.

The users considerations will often help with SEO but not always. In this context you must decide if it makes sense to serve your new section from a sub domain from the point of view of the user. This means that the content must be distinct and deserving of a site (which a sub domain effectively is) in it’s own right, regardless of SEO considerations. If the concerns of both your users and your SEO needs are aligned by the choice of sub domains well then go with sub domains, if not then stick with the standard issue directory or even the “everything from root” structure. Please ’stick it to me’ via the comment box if you think I’m wrong with something (it’s been known to happen ).

This entry was posted on Wednesday, October 3rd, 2007 at 12:10 pm and is filed under SEO. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.