Subdomain vs Subdirectories
It has been revealed by Matt Cutts that in recent times Google is treating subdomains like the subdirectories of a domain, they hope to limit the number of results that are shown for the given keyword search from the particular website. Previously few of the search marketers tried to use keyworded subdomains for the purpose of promoting search referral traffic from the search engines in the process deploying out a number of keyword subdomains for the conditions for which they expected to rank well.
An article was written about how few of the local directory sites employing the subdomains for the purpose of achieving proper ranking results in the search engines. According to the article the websites were ranking well and this is not due to the presence of keyword as the subdomain. Some of the examples have been shown of sites that ranked well or even better in few of the cases where the keyword was among the Uniform Resource Indent as opposing the subdomain. In Google, subdirectories and the subdomains were functioning for keyword ranking optimization.
A number of sites that possessed different degrees of quality in their subdomaining strategies have been found. If there are subdomains then you must make sure that these include primarily unique content which are reflected on the other domains. It is important to see that the subdomain must contain page content which is not present on the other subdomains since this might lead to spamming of the search engine indices.
Googles Webmaster Guidelines are provided for the particular subject:
There is no necessity of creating subdomains, multiple pages with significantly duplicate content.
A number of large corporate websites have few of the accidental duplicate content, however if you install dozens and hundreds of subdomains with the dupe texts may project that you are attempting to spam the search engines “don’t do it.
If you are looking for the method of structuring the URLs as well as the site content for the purpose of natural search marketing, it is best to use a format of keyword directories and subdirectories instead of the subdomains. It is convenient to manage, and it appears far more natural and reasonable from the perspective of the search engines. There is very less chance of duplicating the content.
A number of major websites host a number of site applications and sections on the subdomains as well as the external providers sending the content on the different servers. However, it is pretty convenient to assign the subdomain to the third party that is providing the service for you. So long there is no duplication of the content of the pages on subdomains there is no problem.
People have enquired several times which is better subdirectory or the subdomain.
For this purpose a different top-level domains (TLDs) are preferred as it provides the opportunity to send a signal to search engines that the content is meant for the different countries. For instance, the French language pages could be delivered on the .FR domains like the www.example.fr
If you are not interested to use the TLDs for the pages of alternate language, there is no need to worry excessively for using the different subdomains versus directory/subdirectories. It is said that the french.example.com will probably function well as www.example.com/french. It is believed that the translated versions of the webpages are not considered to be the duplicate content since they include a number of various texts. The information might be duplicate but not the text content. The pages in the two separate languages may not come for the same keyword search.
TLDs are recommended for the foreign language pages to get best performance. However you can use the convenient methods. Check out before implementing as to which one of these will help you in the long run of your business in terms of traffic to you website through seo.