How do digital music sellers know what religion you are?

Following up on this post about reports of digital music vendors reselling customer data to marketers, many BB readers including Robert asked:

What I want to know is how in the hell can they know your religion ( "The "datacard" says that the company has race, age, gender, religion, and income information on the subscribers." ) when you buy an iPod or use eMusic?

First, Robert, mind your language. Faith-based downloading initiatives frown on indiscriminate use of the word "hell." I don't know the answer to your question, but maybe better-informed readers do — or perhaps a representative of the data resellers in question would like to reply?

Perhaps the "religion" tag results from probability analysis based on song purchases. My beloved iPod contains music I've bought from iTunes, eMusic, and other sources. Among the many files stored: Hell (James Brown), Don't Fear the Reaper (BOC), Gwine Dig a Hole to Put the Devil In (Leadbelly), Devil's Pickney (Sugar Minott), and Sympathy for the Devil (Ozzy). If my hypothesis is proven correct, you'd find my customer data in the "Consort of Satan" column, which would explain all of the "L:@@K! Sell your s0ul for C*h*e*ap* beachfr0nt purgat0ry T1M3sh4res!!!" spams I've been getting lately.

Boing Boing reader Greg was upset about the possibility that his customer data might be resold, and he tells us:

When I cancelled my [eMusic] account and asked them to remove my information from their servers, I got the following:

"Hello: Thank you for contacting eMusic Customer Support. We are sorry to hear of your frustration. Your privacy preferences have been recorded. Please be assured that eMusic has never rented or sold its membership list to any third-party organization. eMusic has no plans to do so in the future. Also please note that your e-mail address and account information are kept secure on our servers. We understand your concerns regarding your account information and apologize for+any frustrations you have encountered.


eMusic Customer Support Team"

So, if that's true (and I don't trust that it is), then maybe it's a different service?

Boing Boing reader Joe and others wrote in to say they'd received the same reply from eMusic.

Previously: EPIC asks: which digital music service is selling your data? (UPDATED)

Update: Reader Luca says:

I am sure that eMusic does not sell their membership list, i.e. the names and email addresses of their subscribers. But that does not mean that they do not sell data on the song downloaded by their members, each with anonymous information about the member who downloaded it (such as race, age, gender, religion and income).