Domain name extension doesn’t really matter in ranking well over the search engines. However, there are several factors that will affect your blog concerning domain extensions.
There is a new domain name extension, “.co” as to "www.yourdomain.co“. Accompanied with it is a discussion to whether or not it is a premium domain extension or not.
Webmaster-source.com says it is a disaster:
“I highly doubt that .CO will be used legitimately for much other than name protection for a similar reason. It looks like a typo.”
Dailyblogtips.com says it’s not worth it:
“I for one won’t be buying any .co domains. My policy with domain names is the following: if the website I am building is a serious project (e.g., a startup, a blog with a big potential, a company website) I always go with a .com, even if I need to spend some money to grab a good domain. If I am building a mini website, on the other hand, I consider the .com but also the .net and .org versions of the domain I want.”
.com is really the king of domains, and .net can be the queen.
.org is best if your blog is an organization. So pick what’s best.
.co, .me, etc…. are just subsidiary domain extensions (though some considered it to be premium domain extensions). However, if you rank well on the search engines, this really won’t matter that much. After all, most people find you on the search engines and not by remembering. They type in keywords and not domain names.
The biggest setback however is about “memory”. Your second time visitor has to remember your domain well. If you have a domain which is very uncommon, then your chances of keeping your visitor longer will be a little far.