Australians loved using Ashley Madison
Sao Paulo, Brazil is the overall winner with 374,542 users.
The population of Sao Paulo is about 11 million, or about half the Australian population in that one city. In other words, about 3% of the population had signed up.
New York: 268, 171
New York has a population of 8.4 million. About 3% again.
Sydney: 251, 813
Sydney has a population of 4.3 million. Almost 6%!
Melbourne: 213, 847
Melbourne has a population of 4.1 million. About 5%.
Brisbane has a population of 2.1 million. Almost 6% again!
Perth has a population of 1.8 million. Just under 5%.