Excuse me, that's not the only reason. When we ask for a billing zip code, it's because IT COSTS US MORE not to have it -- that's a condition imposed by Visa/Mastercard, who charge a higher percentage for transactions lacking a zip code. This is one of the reasons that we always ask people "Can we run this as debit?" if they hand us a debit card; we don't need to ask for a zip code unless it's a credit transaction. And if you give us a different zip code from the one on your billing address, your transaction may not go through when it hits the card service center. This is at root an anti-fraud measure, no matter what other purposes some places may use it for.

I'm not at all surprised that the Forbes article would fail to mention any of this.