Rajasekharan N. asked me the following question a couple of weeks ago:
Do you think it is better to have a shared or fixed IP address?
I confess that I didn’t know the answer right out of my head, so I went to research a bit. What I knew was that a shared IP is what you get most of the times when you sign for a shared hosting plan, and that usually you can get a static (also called fixed or dedicated) IP for a domain adding a couple of bucks to the monthly deal.
Under a shared IP address structure all the sites inside a server will have the same IP, say 126.96.36.199. Once a browser requests a page from a site inside that IP, the server will check what domain is being requested, and it will serve the correct page.
Under a static IP address structure, your site will have a unique IP that identifies it, even if it is hosted on a server with more sites.
Through my research I discovered that there is a small debate among SEOs about the influence of having a static IP address upon the search rankings of a website. Some people claim that it could actually help the rankings, but the majority agree that the sole fact of having a shared of a static IP address should not make any different at all in front of Google or other search engines.
I tend to go with the flow here, and I doubt that having a static IP per se would improve your search rankings.
There are cases where a shared IP could hurt your site though. Suppose one of the websites sharing your IP gets flagged for adult or spam content, or suffers some other strong penalty that extends to the whope IP address. Your website would inevitably suffer the consequences as well.
This is a rare situation, but it could happen.
If your website is growing fast or making a good amount of money, therefore, I think it could be a good idea to grab a dedicated IP. Just in case, as they say. I have booked one for Daily Blog Tips already.