Why would computerworld send me spam?

I know Conde Nast has a spam addiction, but why is Computerworld sending me marketing emails? It's a bit weird. My guess is that they use a very old fashioned email address for opt-in email, and that spam using one of my email addresses hit their opt-in list.

The reason I suspect this is that their opt-out process requires an email address to be submitted, which is also archaic.

I'm filtering all their email to the trash now, so if they want to send me a note they'll have to use the comments to this post. If they'd had a one-click embedded link opt-out I'd have given them another chance, but if they're not guilty of spam they're certainly guilty of technical incompetence. Firing offense either way.