I want to do blog.mysite.com but i know it will negatively impact my PR with Google. When is it preferable to structure your site like that vs mysite.com/blog? Is it only for the benefit of PR?

  • 1
    Dup Jul 20, 2010 at 18:17
  • not a dupe... they don't ask about why one is better than the other but rather why traffic increases when moving from one to the other
    – Jason
    Jul 20, 2010 at 18:59

6 Answers 6


The only time I would use a subdomain is if the site is truly a "different site". Take for example my business site I have the following setup.

http://www.iowacomputergurus.com - Business site

http://productsupport.iowacomputergurus.com - Bug Report Site

http://customersupport.iowacomputergurus.com - Customer Helpdesk site

Using this structure all of the business stuff, including the blog is on the one site, but the stuff that is truly different, the various support sites are offloaded to sub domains so that they are separate.

In my opinion, if you REALLY want to use blog.mysite.com say for ease of remembering, setup a 301 redirect that takes users to http://www.mysite.com/blog or something similar.

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    +1: Matt Cutts (Google's alter-ego) suggests to do this too: A subdomain can be useful to separate out content that is completely different. Google uses subdomains for distinct products such news.google.com or maps.google.com, for example [ref. mattcutts.com/blog/subdomains-and-subdirectories/] Mar 28, 2011 at 13:05
  • Keep in mind that Matt Cutts doesn't say this is better for SEO as is often implied when someone says he recommends something. In this case it's because it's easier to manage the content. Not for SEO purposes.
    – John Conde
    Mar 28, 2011 at 13:42

If you DO use subdomains, depending on the sophistication of your target audience, be prepared for users to add www. in front of the host name automatically (www.blog.example.com). Setting DNS up to support this is something that I've never taken the time to figure out; it's possible but takes more effort than just adding another CNAME.

  • yeah i've definitely heard this. stupid unwashed masses and their dubyas
    – Jason
    Jul 20, 2010 at 19:51
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    @Jason: masses can be silly, but if they are potential customers I wouldn't loose them just for a 'www'. Non-geeks-people are more willing to trust a domain that starts with 'www', so they are more willing to click on in it when shown in SERPs compared to a site without the 'www'. Mar 28, 2011 at 12:18

The usual recommendation we hear from SEO consultants is that you should really only use a sub-domain for short-lived "micro-site" type content, and all long-term content should live on the main site.

As others have pointed out, you lose some of the "authority" (and therefore Page Rank, etc.) of the main site when you go out to a sub-domain because they are treated as separate sites - you've clearly decided that you don't want the content on the "main" site, therefore it is less relevant.


Analytics tend to be a lot easier when you don't have sub-domains.

  • could you plz explain a bit more?! Mar 28, 2011 at 12:21
  • @Marco For example, Google Analytics can't differentiate between identical folder structures under different subdomains. a.foo.com/example/ and b.foo.com/example/ would both show up as /example/ in google analytics.
    – furtive
    Apr 2, 2011 at 23:55

First and foremost for the benefit of users. Words before a domain are usually typed in, whereas words after are often left out. The user usually expects to be able to navigate to the path after the domain themselves.

Where this is not the case (nested links to get there) or the navigation changes drastically (which it can in a blog) then it is not really the impression you want to leave for someone who has bothered to type in an address to their address bar.

The PR of your site will only be negatively impacted upon if the blog is unrelated (treat it as a PR building hub site). If it is not unrelated then it should be a boon.


if you’d like to build the equity of one web site, I suggest using a subfolder.

If you’d like to build an entire new entity with its own equity, launch a subdomain

Read more: http://www.searchenginejournal.com/subdomains-or-subfolders-which-are-better-for-seo/6849/

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