Prevent Auto Click by PHP?

I want to create a web app.
User will have an account with a link look like :

If anyone click on their links, they will get points

But how to prevent using softwares which can click on their banner automatically.
The first time, i think it should use session, cookie, or defining IP ($_SEVER[]) but all of them are useless (they can change IP, delete cookie easily) !!!
I don’t know what i can do ???