Magnatune's checkout system doesn't actually ask for the gender of a buyer, so I had to manufacture the gender data from the name people give when buying.
The US Census web site provides flat text files of the most common men's and women's first names. I wrote a program to look up each Magnatune purchaser's name against the US Census first names list, and thus assign a gender. It's suprising how many names appear in both genders (ie, Leslie, Kelly). Oddly, some clearly male names (John, Steven) appear as infrequent female names. I assumed that these were errors in the census data, and corrected those by hand. Other conflicts, I resolved by hand. The remaining 100 or so names that were in both lists I left in the 'male' category as a visual spot-check seemed to confirm they were mostly male. In retrospect, I should have used the "frequency" percent which the census provides to decide what gender a conflicting name was mostly likely to fall into, but I think my method is mostly accurate. Given that the US is fairly multi-cultural, as is Magnatune's customer base, the Census names cover a wide range of cultures (many Asian first names appear) and is likely relevant in this case.
How much data did I have to work with? 94% of Magnatune purchasers give their name, and of those, the Census files identified 80% of them as belonging to a specific gender. In other words, 75% of purchases were successfully identified with a gender.
Without further ado, here is the first chart:
Notes on the chart:
* Men account for 89% of Magnatune sales, women account for 11%
* the gender sales gap is narrowing, from 91% male/9% female a year ago to 84% male/16% female this month (November 2004)
* since November, the gender gap has narrowed quicker (perhaps because of the Christmas season, or Magnatune introducing physical CDs)
I also wanted to see if men or women paid more for music (since Magnatune allows buyers to choose how much they want to pay, from $5 to $18), and so I charted average purchase price by gender:
Notes on the chart:
* there is a slight difference, with an average of $8.23 paid by men, versus $8.14 by women.
* the "gender pricing gap" is widening, although this widening is entirely due to the past 3 months, which may be Christmas or the physical-CD-introduction at Magnatune.
* With the past 3 months removed, the price women pay was increasing significantly, as was the price men pay, though at a less steep curve. We will have to see if the past 3 months are a permanent or seasonal trend.