This add-on is not just a revenue sharing add-on... admins can use it as an Ad Manager and you also have to ability to sell 'packages' (you can include more than one ad zone per package) which users can buy.
I took the time to look into the add-on and one thing is that the add-on is pretty cool considering it's free but has loads of limitations... like the ads will only be shown in the 'message' template only and with mine, you can show the ad anywhere available
There are also loads of things like a better user criteria system, etc...