So I do some SEO freelance on the side. But recently I have been building small sites for some of my clients and just hosting them on my hosting account since I have unlimited domains. Of course I am putting a link in their footer back to my SEO Website. But these links are on the same IP so they may not be worth as much to Google. So the question is...do I set up a hosting at an SEO Host so that each of these client sites are on a Class C IP address? Or should I not even worry about it? Keep in mind it is cheaper to host them on my Host Account.
I wouldn't worry about it. You could swap links with another person doing similar work if you wanted to. IE- you link to his sites and he links to yours, instead of each linking to your own.
Just a word of advice, always do backup of your clients sites. Sometimes unlimited is not always as they seems. Also from what I know links from the same IP should not be that effective but I used to cross link between my sites in the same niche and they were working just fine.
Yeah I read some threads over at the Google webmaster forum and they mostly said do not worry about having websites on the same IP that link to each other. Unless they all are interlinked which will look like a scam.