The average salary in Australia is $55k, the average in the Philippines is $3.9k. Not taking in to account disposable income that's about a factor of 15. The entire philippines only has 4 times the population of Australia. The 2 markets aren't even comparable.

User value to companies that serve advertising is based on what companies are willing to pay to serve ads to them. Which is directly tied to the monetary value of that users business to the company buying the advertisement.