How are sub-domains treated and pageranked by Google?

[Rebtl]

I have never used sub-domains before but for a new site that I am planning I want to.

I am wondering how sub-domains are treated by google as far as rankings and page rank go.

For example how will:

keyword.mydomain.com

compare to

mydomainkeyword.com

I guess basically my question is will Google treat my subdomain the same in ranking as if I had bought it as one single root domain?

Thanks

Rebtl

[bgmacaw]

In most cases the sub-domain is treated as part of the the main domain. There do seem to be a few exceptions to this around for a few very high authority sites like Google's own Blogger/Blogspot and WordPress.com but what goes for them doesn't apply to us mere mortals.

As always, each individual page has its own PR and search engine placement. Consider any links to be counted as internal, not external, links. Having a keyword in the subdomain can help some but it's a poor substitute for having it as the top level domain name.

[Rebtl]

Yea thats what I was afraid of.

I am planning to build a site and I want to rank for a keyword that changes often.

By that I mean, it will be something like

january.newyorktimesbestsellers.com

That is not it obviously, but the same plan. The base keyword will stay the same all of the time, but the time period will always change.

So would putting the time period in the sub-domain still get me good rankings if the word is somewhat competitive? Or should I just buy januarynewyorktimesbestsellers.com every month (again this is just an example)

I am thinking it may be a difference between long term and short term.

Long term: the root domain gains page rank with the monthly additions, and this gains google trust and starts automatically getting ranked higher.

Short term: I buy the whole keyword in the tld and get ranked higher faster because the whole keyword is in the ltd.


Any thoughts or advice is appreceiated

Thanks

Rebtl

[bgmacaw]

Here's what I've noted with my own sites.

An exact top level domain name match with a search term does well with only minimal link building in most, but not all, cases.

Subdomains tend to do best on shorter TLD's that aren't keyword focused so that Google has to grab onto the subdomain name name for relevance. For example, a domain named hjk47.com. Subdomains where there's a recognizable keyword in the TLD don't do as well.