Rich,

It certainly cant hurt, as mentioned though, if you are still just using sponsor provided free content, make sure you are allowed to promote multiple sites from the same sponsor with that content.

If you are using your own content, i see you just purchased a couple of sets from Rainbow Content, then you can promote pretty much whatever you want on your sites, just make sure that you build them to stay within the rules of the places you are submitting to and that the sites you are using, match the niche of the content

Regards,

Lee