With the Ad Sharing plugin for multisite I have some questions?

First most basic question is how to you get ad codes besides Adsense? I would like to create my own ads also like in DoubleClick Publisher or with the Wordpress plugin Advertising Pro and make ad codes. Is that possible? For example: in the demo video, where does the wpmudev ad come from? Where did you generate the ad code?

Second, how do my users get paid from the ads? I see the percentage split in the options, but nothing about registering to get paid?

Third, if my users are to be paid, how to I track impressions and clicks on the ads on their sites?