There are a lot of companies out there starting hosting for search engine optimization. The claims that C class IP’s can help you have better ranking in the search engines have not been proven, but it is catching on quickly.
Basically the thought behind the concept is that if you have multiple C class IP’s and the content is similar you can link them together andGoogle or other serch engines will see them as completely unrelated websites on the server end of it. How is that?

Generally when you pay for hosting you have all your sites or accounts all on one server which has a default IP for all of the sites on that server. Most of the time dedicated IP’s can be purchased by a host but these are not C class IP’s.

A Class IP consists of the third set of the number being the C class. For example, 74.67.44 shows the 44 spot to be the C class. So a different C class would consist of 74.67.45 as being a different C class.

Whether the true effect of the C class is true or not there are companies starting left and right to start making this available to customers. If you will be linking sites together with similar content this may be helpful to the growth of your sites. But you be the judge of that.