Smorty.com are a company that pay you to post. They have noticed that bloggers who write a lot of sponsored posts have been penalised by Google by having their page rank lowered. They have therefore produced some useful suggestions for bloggers who are suffering :
To remove all sponsored post tags on your website. I have therefore put a sitewide disclaimer on my websites and stopped putting - 'post sponsored by...' unless an advertiser has specifically requested that I do so. They also suggest removing any adverts such as 'review me' or 'hire me' which would suggest that you write sponsoed posts. I have therefore decided to removed my advertisement for Pay Per Post in my side bar.