Is there a way in Unity to know when an ad was clicked? Some plugins for different advertising networks have events that fire when the ad was clicked, but if there is no such event - how do I know when an ad was clicked?
There is. I hope you know that through the advanced analytic options inside of the google adsense you can get a lot data.
You could add a blank field across the onGUI funcion. For every touch, in the spot where the ad shows up send packet to your server. Just with location. Your server will know that someone clicked, while you will not have to worry about trolls that love changing their phone time.