Can subdomains be configured to contribute towards the base domain for SEO ?

According to this video

http://www.youtube.com/watch?v=_MswMYk05tk

there is no difference as to having subdirectories and/or subdomains.

I have 4 domains ( like this www.domain.com , second.domain.com , blog.domain.com , commerce.domain.com, etc) that all share a root domain ( domain.com ) but all 4 have different PR ratings from Google. Alexa does show the same rank, but google has all different PRs for each domain. This leads me to think that google does treat these domains separate for SEO rankings but what I want instead is for Google to calculate all SEO as this was all one domain. For example my blog ( blog.domain.com) is where most updates are happening and I am probably loosing out as these updates are not counting as "fresh content" towards the primary domain ( domain.com) which is what i want.


Further in Google Analytics / Admin /Tracking Info, there is a configuration setting "Subdomain of domain.com". For each of my four domains this is enabled however I its not clear whether that actually tells Google to combine SEO as its one domain or treat SEO as if they are independent domains. ??

Info apprciated

 

A sub directory can contribute to a root site but sub domain carries a separate rank.

 

Google treats them different in fact treats every page even like:
domain.com
domain.com/page1.html
domain.com/anotherpage.html

To Google those are 3 completely different.

To contribute one to another is simple to give backlinks from one to another (internal linking) so yes not much to do to benefit each other.

When a searcher types in a keyword in Google it returns a page not a website, the page it returns is what it deems most related (based on anchor text of its backlinks that's most imp) and most fresh/important/etc (based on who links to it and how many links it get, and other backlink factors).

Jack

 

Google take subdomain is independent domain and separate site from your main domain name. That is why Google give different ranking to your domain and subdomain .
Alexa ranking is different because it take it as the same domain.

If you wish to get benefit from your blog and so on , try to turn your subdomain to subfolder .
So google will recognize it as the same .