"You can expect positive effects on your future."
Translation:Tu peux attendre des effets positifs sur ton avenir.
The two don't mean the same thing. "in your future" means that you will see positive effects later, even if they don't really affect you personally that much. "on your future" means that your future will be affected positively, maybe your chances of getting that job you dream about will be increased.
I hope that makes sense, the distinction is a little hard to explain. :)