With the Ashley-Madison data hack in the news, a data visualization web site created a bar graph showing the cities with the highest number of AM accounts.
[Note: As of 12/29/2017 the above link was disabled. The same chart was available here.]
There are 268,171 accounts in New York City and only 86,897 in Atlanta. So what? There are a heck of a lot more people in NYC (8.406 million) than in Atlanta (447,841). It's no surprise that NYC has more Ashley-Madison users than Atlanta. I bet NYC has more XBox Live accounts too.
As one of my colleagues likes to say "Where there's a lot of stuff, there's a lot of stuff". This data is meaningless without per-capita reporting.
In New York City, 268,171 accounts out of a population of 8,406,000 is 3.2% of the population. For Atlanta, 86,897 accounts out of a population of 447,841 is a whopping 19.4% of the population.
In other words, even though New York has roughly three times as many accounts as Atlanta, Atlantans are SIX TIMES more likely than New Yorkers to be on the site.