Affiliates for mobile app with 8$ CPI? How this is possible?

Hi, i'm new at affiliates marketing

I want to promote an Antivirus App on facebook and make money by CPI commisions.
I found this website yesterday, it show that the app NortonGBWAP Anti-Virus offer 8$ per install.

hxxps://bizprofits.com/cpa-offers/nortongbwap-anti-virus/

I don't understand how this could be possible, how they make money if they pay me that much only for getting an install from me..?

How it's work? On the image, it's look like if they ask for the user's phone number, so the link don't redirect poeple to Google play? I think that asking for the phone number is a huge turn off..no?

And, in the description the say that the Geos is for UK, does it mean that they only want me to promote the app in UK?

Thank you everyone!

Usually they are based on monthly subscriptions means that the app withdraws money every month from the user. And Yes, it will be available only for UK users other countries will not be converted, but usually CPA networks display country relevant offers in case if it is clicked outside the UK in your case.

It's weird that they ask for the phone number before bringing poeple on the google play appstore page