A dedicated IP brings a number of benefits for anyone looking to be found on the major search engines, which is obviously the key factor in raising business profile. Even though the search engines try to closely guard the ways in which they evaluate and rank websites, there is an acceptance that IP addresses can impact on the final ranking of a site.
A shared IP address means that your website will be linked in with other sites during this process, which can have a negative impact for two reasons. If the quality of the other sites is very low, it is likely to drag down the rating applied to your site. Also, if you own a number of sites, it would be of benefit to place links to each other on your different sites.
Using a dedicated IP for each site means that links between the sites will be given greater prominence by the search engine, providing a great starting point for increasing the number of legitimate links you have pointing towards your site.