Advantages of Sub Domains

Points to consider before using subdomains Subdomain makes the URLs shorter and nicer. It allows website owners to categorize the content of the website. It also helps in improving the search engine rankings as most of the search engines treat the subdomain as a separate website address. However, there are certain things to consider before setting up subdomains for your website. Many web hosting providers do not provide subdomains in their hosting packages. If you have subdomain and want to move your site, you have to choose one which supports subdomains. Most web hosts charge extra for subdomain setup and maintenance. If you use cookies in your website, a cookie set from a subdomain cannot be read from the main domain and vice versa because of the security association feature tied to the domain which set it. This is also true for session cookies, where, if the user is logged in on the main site, and then moves to a subdomain, the subdomain site will not be able to access the same session cookie, and will assign a new session (hence forcing the user to login again). However, session persistence across subdomains can be maintained by implementing URL rewriting instead of session cookies. Your website stats will often not include the statistics of the subdomains. Therefore, you have to setup separate statistics for your subdomains. One of the advantages of using subdomain is that the website can be broken down into smaller pieces without losing the brand image associated with the domain name. The subdomains can be hosted on separate servers in order to reduce the burden on the main domain hosting server. Second Tier Subdomains You have a website. You spend alot of time building it, refining it, tweaking it into oblivion to get the search engine results you are looking for, yet you don't get visitors. We have all heard by now the advantages of having a blog for promoting your website. When I suggest this to my clients, the number one answer I get is "Then I have to pay for another hosting package..." No you don't. You put it on a subdomain. Example: www.yoursite.com will be your main domain www.blog.yoursite.com will be where your blog resides. Once you have your blog, adding a link to it on your menu takes a couple of seconds, and voila - your blog is up and running. This is the part where you feverishly start posting articles about your niche market, your product, or your service, and link to your website from each article. Blogs are amazing: Search Engines love them, and they generally get good PR very quickly. This means, by default, that if your blog outranks your site in terms of PR, every link to your main site from your blog is a QUALITY INBOUND LINK... You can further up the PR on your main site by deeplinking (linking to other pages on your site, not only the landing/home page) to your site. Sharing cookies among all subdomains As explained earlier, cookies are not shared among subdomains or between the domain and the subdomain. In order to set cookies accessible by all subdomains, use the following techniques: While writing the cookie, set the cookie domain to ".domain.ext" so that it applies to all subdomains. If the cookie domain is set to ".domain.ext", it will not be accessible by a user who types in the address without the www before the domain (i.e. http://domain.ext). Therefore, redirect all requests without www to http://www.domain.ext. There are some reported problems with the above approach. It is safe to set the default cookie with no domain specified and then set another one with domain as ".domain.ext". In this case there is no need for the redirects. However, remember that session cookies are set by the web server software and you may not have control over how the cookie domain is set.