Hello All,

I have a question about how search engines view sub domains of the same URL. I'm building out a site for web site design services. Like many companies, we're going to offer hosting, web site design, maintenance, shopping carts, etc.

I am going to set up hosting.mysite.com for the hosting portion, design.mysite.com for design, maintenance.mysite.com for maintenance, and so on.

Do search engines view each of these sub domains as independent web sites, or simply a part of the main www.mysite.com? When working on a link popularity campaign, will I need to establish links to each sub domain, or does a link count for the entire URL and all sub domains?

Ultimately my big question is how search engines will treat the URLs. Since we plan on having a good deal of content for each portion, we are going to have independent web sites for each service line and optimize for each. Right now we're just trying to decide if unique URLs are necessary or if we can build our brand name via offline advertising and simply have sub domains for the online portion.

So much to learn in so little time. Thanks!

It depends on the procedure, how you are treating the sub domain. Actually SE will treat the sub domain as independent site. Usually if one wants to promote the sub domain then they give link to it from main domain. so sub domain gets automatically promotion from main domain. When search engine will take links from main domain it will treat it as one single domain (main+sub). but when it comes to promotion (link popularity campaign), one needs to promote the sub domain independently.
When someone will search for keyword, he will get the main domain first then sub domain (in case if the link has been given to sub domain which is targeted for the keyword).usually when SE rank the websites, popular ones are listed manually by giving more priority to that page.

Other views are welcome if I am wrong

We have spoken to Google numerous times about whether or not sub-domains are seen as part of a main domain. They have assured us that generally they are not. If they were, this would create problems in the many ccTld countries like the UK, Australia, China, Brazil, and Argentina where it is most common for domains to be registered at the third level. Examples are "domain.co.uk" for the UK or "domain.com.au" for Australia.

Here are two very different sub-domain web sites that are technically on the main domain of co.uk...

{ edited as per TOS}

In Australia, these are very different sites yet they are technically sub-domains on the same main domain...

{ edited }

It wouldn't make sense for Google to treat them the same at all and Google knows that. They don't treat sub-domains as part of the main domain. To understand why you have to go back to the origins of the Domain Name System http://www.isi.edu/in-notes/rfc1591.txt. If you study it, you will see that the domain name system was always meant to be hierarchical and that sub-domains were always meant to be treated as different places online.

In the US we are a bit spoiled. With the exception of many schools, military, and government sites, we have a tradition of registering and using domains at the second level (domain.com or domain.net, etc). This is not the case in much of the world and Google knows this. It wouldn't be right for them to treat all sub-domains as part of a main domain. They could end up punishing one user for the errors of a completely separate entity.

Of course Google isn't going to expose their exact algorithms and many SEO experts have tested this theory finding diverse results. When Google discovers that someone is "playing" their system, they will penalize them. But as a standard and in the absence of any skullduggery, sub-domains are generally treated as separate sites.

[ Message was edited by: Dinkar 01/24/2007 07:42 am ... Reason: Links edited as per TOS ]


[ Message was edited by: joezeppy 01/24/2007 10:31 am ]

Joe - you'll want to edit that post - we generally don't allow link dropping. In this case, you may be trying to provide links as example to explain the info you're posting, but I've flagged this post for a look-see by the forum mod - we, under no circumstances, allow link to adult websites, for any reason.

Not trying to bust you for being helpful here, but the ToS are very clear.

& sub domains are treated as separate websites...

In a lot of cases (but not all) there is more strength in going for folders (for websites of related theme) rather than creating sub domains.

No problem regarding the edits. I understand; should have thought of that. My point was to say that in many of the ccTlds, it would be wrong to penalize one domain owner whose content was very different than another.