This is for the webmasters who are holding more than one websites.We all know very well that google and other search engines do consider the Class c while giving page rank and rankings.we can mix out it with hosting our websites on different hosts for different ip’s which will affect our rankings also.With Multiple C Class IP Hosting, each IP address will have its own C number. This is one of the best ways to boost your site’s ranking on the search results. These addresses are specially designed for small sites and blogs.Classes with a different IP address, you can use the network or related links to your main page with a minimal or say no risk of getting penalized by search engines.

Below are some of advantages which david967 from cnet forum shows us:
1. You can create back links for your websites from a single hosting account managed from your control panel.
2. You can host multiple sites under a single hosting package with multiple C Class IP addresses.
3. You can host small or large scale websites with larger bandwidth and disk space as per requirements.
4. Choice of cPanel [Linux] or Plesk [Windows 2003] control panel
5. And the best thing is that it is the most affordable.

And about Virtual and dedicated Ip addresses this is the comment from mattcutts

Links to virtually hosted domains are treated the same as links to domains on dedicated IP addresses.