I was doing a Google search to find out if hosting a domain name with cPanel’s add-on domain feature had a negative effect on SEO. I ran into a thread on Digital Point where another fellow asked basically the same question. The conversation somehow evolved into a discussion of hosting websites with the same IP and if there was a negative effect. You can see the thread by clicking here.
The main poster in that forum brought about some good arguments for not worrying about hosting websites on the same server with the same IP address. One of the main reasons is that even if you are doing shared hosting, you have a great chance of being on the same server with the same IP address anyways. If it is a ding on your SEO, it can’t be a very big one because most people only use hostgator or Godaddy hosting anyways.
Just another reason to not worry about latest SEO craze that will only cost you time, money and worry. Your focus should be on good quality content that will keep the users coming back for more and get you great inbound links. Just my opinion.