SEO for domain mapping

If I have abc.blogger.com and have abc.com pointing on that blogger site so when I open abc.com it will read abc.blogger.com (not redirected).

how does the SEO works for both of them? Which we have results in Google search? abc.blogger.com or abc.com?

Well that depends on how you have it configured. You say that it’s not redirected, so how are you showing the content of abc.blogger.com on abc.com? Are you using an iframe?

If you have the option, you’re best avenue in terms of SEO and ranking would be to place a 301 redirect on abc.com to abc.blogger.com so that you don’t have duplicate content and to keep your visitors from questioning the correct address.

It is similar like this plugin do http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/

If you’re mapping your domain like that you’re actually creating duplicate content which makes one of your blogs (because there’s two of them now) worthless without using rel=“canonical”.

Higher PR site will be got high Google SERP, no matter you are blog or website.
one more thing, the nofollow and dofollow mark in the URL also will determine the google SERP result.

Rather than using a 301, you could use mod_rewrite, which would ensure that not only is the homepage redirected but people could also type in abc.com/page and be taken to abc.blogger.com/page

Not only is this incorrect, but it has nothing to do with the question asked.

Stevie, yes - you’re correct but that is also a 301. The 301 is just the headers sent with the redirect. Most people refer to the redirect in general as a 301. Generally (on Apache) it’s done with a .htaccess file using mod_rewrite but it doesn’t need to be to achieve the same desired effect.

What does 301 redirect affect to SEO?

A 301 will pass all SEO value to the new URL.

You’re right, that was sloppy writing on my part. I was trying to get across the difference between using mod_rewrite to re-map a whole load of pages and using “Redirect 301” lines, which is great for individual pages but quickly becomes a nightmare if you try to do site-wide changes in that way.

It tells the search engines that it’s the same page as you had before, just with a new URL, so all your rankings and reputation get transferred from the old page to the new one, and the search engines will replace the old URL with the new one in their indexes.

I figured it was one of those situations where we should listen to what you mean and not what you say. (:

Do you have a snippet for the .htaccess file that will map pages from one domain to another? I remember doing this in the past but can’t seem to remember exactly where I did it which means my code is lost forever. I’d love to add this back to my bag of tricks.

# redirect from old domain to new domain
RewriteEngine On
RewriteRule ^(.*)$ http://www.example.com/$1 [R=301,L]