There has been a surge of sponsored review services that are available as a form of online advertising that appeal to both advertisers and "some" bloggers.  How do bloggers get paid without losing the quality of content?  The issue that keeps coming up is..how credible is the review if the blogger is getting paid?  A solid and reliable rating system would certainly help.  If a rating system could be developed that rated paid and non paid bloggers in a uniform way, this could help the issue about content quality.  If you want sponsored reviews, there is a new site called moguling.com that you should check out.  They're working through an internal procedure for doing just that.