Moving to a dedicated server is a big decision for your company, moving too soon can put unnecessary strain on your cash flow.
Moving to a dedicated server can have a positive impact on your site we will examine the positive factors first.
Not Sharing Bandwidth - For many the decision to move to a dedicated server will be influenced by a lack of bandwidth observed when their shared hosting package starts to run too, it should be noted that the cause of this can be:
a. High traffic on your site
b. High traffic on another site on the same shared server.
You may well be one of the luck shared web hosting customers that find themselves on a server with a lot of sites which attract little traffic.
Unlimited Data Transfer - Many shared web hosting packages market themselves as having ‘unlimited’ data-transfer, this is not strictly true they may not charge you for using excessive data transfer, they will just throttle back your bandwidth.
Your own IP address - Most people don’t realise the benefits of having your own IP when in actual fact it can have an extremely positive impact on your search engine positions. If one of the other sites on your shared server ‘which you have no control of’ has fallen foul of Google, the Big G may view your IP as being a bad neighbourhood. Often the increase in traffic this can bring will pay for the server itself.
Control over your settings and software - A dedicated server allows your complete control over the software you run on your server so you don’t have to make do with the standard operating systems and software commercially available on shared servers
Source: http://www.ezinearticles.com/