I accept zero confirmation transactions at my brick and mortar store and it works perfectly, people can also use payment processors for instant transactions as well of course.
...until it doesn't. While it may be workable for some businesses, it's certainly not safe and will never be. In your case, you're just agreeing to swallow losses in case of an easily executed double-spend.
This is true but because they are small purchases it works out alright, however for larger purchases I would recommend that everyone should wait for at least a few confirmations. lol