Review Referral Site

Hello, I run a review website which refers back to and hopes to drive traffic to seller’s sites. I am looking for a system which will track how many times a link is used to go to a seller’s website so that I can charge a nominal fee per click through. The system must be able to record how many times it has been clicked in a time period. I am also looking for a way to track how many times an ad banner is displayed, viewed and clicked on in a given time period. Any pointers towards plugins and setting these up would be great.