I don't know, and it's a good question.

I wonder if it has something to do with it being (for now) a local business. I am extremely wary of using my debit card online. The credit card comes with a lot of protection if the information is stolen. A debit card lets them empty my bank account. In theory, I can get it back -- eventually.

If somebody who has stolen a debit card tries to use it in person, they're running a much higher risk. So the marijuana sellers may have an easier time getting access to that network.

That's purely speculation, however. I know effectively nothing about the business.