Translation of ausschlaggebend

I have contacted you 12 months ago to propose your school's inclusion in our language school directory. I wanted to inform you that our site achieved high positions in search engines last month.
I've also looked at the interface, and found it a good idea to include the colloquial option. Would it be very complicated to add the most important regional check box, like Spain, South America or Central America?
I'm fine. I hope you are too. Art is very important for people and everything would be much more boring without art. Nevertheless, there are not many people who appreciate it. I have no sympathy for that.