Types of Domain Name
Being a web designer and SEO developer for my day job I have encountered many different domain names when setting up websites for clients, a lot of different extensions are unknown to your everyday internet surfer or amateur publisher.
I have used many different hosting providers and registrars and upon using the domain search tools I discovered some obscure URL extensions that I want to talk about and also their effects on search engine ranking and how users react to each type.
Domain Name Registration
As you can see in the image to the right, there are a lot of country extensions such as .ru(Russia), .eu(Europe), .us(United States) and .es(Spain).
You probably know that .us is the Top Level Domain in the United States but .com is more widely used since it refers to companies and the same goes for the United Kingdom where .co.uk is seen more often than simply .uk.
One new domain extension that has recently become available is .me or .me.uk and this is supposed to only refer to non profit making websites such as personal blogs but you don't have to follow these rules if it is the only domain left which is available with your product keyword I don't see what is stopping someone registering 'BuyClothesFor.me' for example.
People even utilize other extensions for example, 'startagreat.biz' or 'gettingyourwebsite.in', although .in is the country code for India and will only get favorable rankings in Google India.
Domains and SEO
Google have already stated that they have no bias towards whether your site is a .com, .net, .info or .biz, I cannot find the particular link to show you this at this time but through setting up hundreds of sites I have managed to get .org, .info, .biz and even .name extensions on the first page of Google for highly searched keywords.
If you want an example, go to Google UK and type PDQ and you will see my site pdq.name is ranking about 6-7th. PDQ gets a few thousand searches a month because it is a popular term for payment processing.
The only time Google favors a particular extension is when it is wants to show results for a particular country and then it will use sites with the country extension such as .co.uk, but with certain top level domains such as .info you can set which country you want Google to associate your site with. Here is a list of sites you can set Geo-targeting to in Webmaster Tools: Google TLDs
3rd Photo Courtesy of Ivanpw
Some domains such as uk.com and us.com are sold by independently owned registry providers, one such provider is CentralNic and they made it possible to purchase alternatives to the domains such as .uk and .us already owned by particular countries.
However, when you visit a hosting provider to set up your website, not all of them will be able to offer you such domain names and I have had problems transferring a .uk.com from registrar to registrar in the past.
4th Photo Courtesy of bloggingbookshelf
5th Photo Courtesy of querkmachine