Why do ad views in USA make so much more money than other countries?

Whereas reviewing the advert efficiency in Unity Advertisements, I seen one thing attention-grabbing:

Simply 4 advert views within the USA have generated nearly 1.5 instances the income of 148 advert views from different international locations. I perceive the decrease income per advert in India, given it’s a growing nation, however what about Canada and Australia? Shouldn't their income per advert be nearer to that of the USA?

A little bit of context:

I don't have a background in recreation improvement, as I studied and work in accounting and finance. Nonetheless, I lately began studying recreation improvement as a interest and revealed a small puzzle recreation on Play Retailer simply few days in the past, which has gathered round 30-35 downloads thus far. Whereas the whole advert income is insignificant, it’s nonetheless an achievement for me