The article wasn't clear, but the survey was done of 2,000 customers (1,000 each OS) done by a US company (I believe a startup) designed to connect it's custome

The article wasn't clear, but the survey was done of 2,000 customers (1,000 each OS) done by a US company (I believe a startup) designed to connect it's customers with discounts at US stores. While it's possible (it's an app/website) that non-US users exist, it seems unlikely anyone would sign up if they were outside the US.