As I understand it, if you have received a payment - perhaps you are an online drug dealer, perhaps you are committing cybercrimes and this is a random payment or payment from your other criminal friends - you could walk up to the bitcoin ATM and withdraw cash without leaving any kind of record.
If you wish to buy illegal drugs online, you could presumably walk up to that ATM and buy bitcoins somehow.
Obviously, the shop owner is getting paid something for the machine being there, probably a fee per transaction, just like ATMs.
Due to this connection with crime, I do not realistically see these machines being around long. That is essentially what they are good for. There are a bunch of online drug dealers. They basically know someone who can source them the goods. They go online and basically maintain their store page, which is very similar to an ebay merchant page. As orders come in, they fill them, put prepaid package stamps, presumably bought online anonymously somehow, and then stick them in random post office drop boxes.
They can then pay their supplier with bitcoins, and their supplier can withdraw them via this method. Their supplier could also mail the ‘re-up’ (restock) so the 2 criminals need not even meet.
It’s obviously significantly lower risk in a couple of key ways. It is far more difficult for the authorities to track them down. Technically it is nearly impossible if the criminals don’t make a mistake. The other, even bigger risk reduction, is that since the drug dealers don’t meet their clients in person, there aren’t going to be armed robberies happening. The drug dealer need not even carry a gun, except when he goes to meet his supplier.
You could argue it both ways, on the one hand, it makes it easier for the criminals to go about their business without being punished. On the other, it reduces the number of people murdered in the drug trade, and it increases quality, and technically it saves the State money because if it can’t catch people, it doesn’t have to spend money incarcerating them.