I'm trying to comprehend how it works... is the no. of times your ad is displayed in the co-op network based on the number of page views or the no. of times someone actually clicks on on of your own adverts on your site?
Neither. It's based on your weight within the network. The more ads you show (more involved than just that though) the more they show yours. Else where you'll find an explanation of how exactly your weight is calculated.
The biggest factor is how many pages you display ads on as a whole, individual impressions and click through have nothing to do with it (those can both be spoofed).