Hi, -I have question does subdomain helps in google PR. -I have blog hosting site which offer free blog hosting services the site is growing steadily so i have question in mind that if i have a link that is spread on all the subdomains i.e on users blogs does it helps in increase in PR or any search engine rankings? -I have doubt in mind that google do consider it a seprate site or not though hosted on the same ip. -As english is not my primary languge so if someones doesnt understand what i am trying to ask i will try to explain again. Regards.
Google (And the other SE) considers subdomains as diferent websites, but the links (if they are hosted on the same server and same ip) have less value. That's what you were asking?
Yeah Google consider is another site but it didnt harm as spam? as subdomain are hosted on the same ip currently 160 subdomain so it wount harm if i sale links or place mine ?
not necesary but its possible if all your subdomains contains spam, look at blogger.com, it has thounsand and thousand of subdomains with blogs hosted, many of them are spam and the main domain isnt harmed.
It doesn't matter if it's a subdomain, sub-folder or a completely different domain. It's based solely on the page you have a link on. For example if you create a page in digitalpoint.com that links to something, but that page is PR0 (because nothing in digitalpoint.com links to it), it's of no benefit. For PageRank measurements, you can completely forget about what domain it's hosted on. It's PageRank, not SiteRank.
My experience is that Subdomains are treated as completely differnt websites and they will need to have link popularity built for them on an individual basis. I agree with malekov, spam on a subdomain probably won't hurt the main domain.