So, is it actual discrimination, or is it just that their data Facebook has shows that other ads are better suited to them, statistically, in terms of profit? I'm sure all sorts of patterns show up in the quantity of data they have, and algorithms show ads based on these patterns. It's possible that gender is a factor, but it seems just as likely that there are other patterns (perhaps some common to a given gender) that factor into this result.

Edit: To be clear, I did not read the article, because I don't actually care that much. I just find statistics and patterns interesting. Having worked in insurance in the past, I was always curious about which exact information factored into premiums, and in what way. I know everything from marital status, to job, education, location, age, credit score, and much more, factored into decisions, and not always in ways you may expect -- all based on statistics.