Page Rank is a scam. Google hates these kind of sites that sell links just for the pr and it Google has changed so much since people started doing this that PR is only a small part of the entire system they use now.
I misunderstood the question. You can profit from advertisements which are links to other sites. You can also sell links to other sites, but this is tricky.
You should sell banner space directly to the company rather than links. This is the only way to really help do what your trying to do, but most of the time they don't need this since your already promoting the product for free.