How Much Paid Posts is too much?

I was talking to a fellow blogger this week and he asked me about my Paid Posts and was wondering how much was too much? I told him that to me each blog/site is gonna make there majority of there earning differently. Some will have a large readership and make there money from adsense. Some will have expensive Review Me or text links ads. Or some will have PPP posts. I also said that usually the blog will evolve over time from one to another to many and eventually it might even out. It may take a while or not happen at all but it could. So if your blog makes its money from Paid Posts then so it will have more then another blog. Doesn't mean anything is wrong with it. That is his chosen ( only choice ) of income so him take it.