Zero Click model is paid based on RPM ( Revenue Per Thousand). You will see very few clicks if any but if you have high traffic volume you can make a great deal of money.
Zeroclick is basically the third tier in the advertising market. You have Google, Yahoo, Zero Click.
I personally like zero click because you get paid whether the traffic is good or bad and there are typically no charge backs.
However there is some downside as you may not get the true value of your traffic but there is good and bad in all.