This page explains it pretty well https://www.reddit.com/r/feedthebeast/comments/35mzwp/curse_revenue_sharing/
Thank you for the link, I have red it and also found and read this page https://www.curseforge.com/rewards-program/110-rewards-program-faq
And I sadly it didn't convince me
I did calculations and looked in to the taxing thing that curse would make me to fill out, just like patreon, that I don't understand at all and neither even one of the accountants I know in my country. So cause of taxing issues I can not use curse just like patreon.
While adsense has specific rules or law (or what ever it is called) in my country which for I have found an accountant who managed to set up the local taxing for me for it.
That is why I have still no choice but to stay with Adsense and link people to my website. While it does sound good that modpacks would earn some too but curse gives a lot less then what adsense gives.
So Thank you for the suggestion but for now curse is not an option for me.
But If i manage to find an accountant who knows how these work, then I will definitely will look in to this matter again asap cause the modpack part does sound good! (Thou I'm still searching for years now without success to be honest)