[Nagoyankee]

What I'm going to say isn't based on any stats, but it's based on my own and my friends' experience.

#1 and #5 are really common. #5 is so great that I don't even know the same kind of a service is available in many other countries. You don't have to pay in advance or give your credit card info to anyone. #1 is also common unless you live far from a convenience store or post office. You only need to show the clerk your bill and pay.

The next most common would be #4. People tend to prefer using the plastic when they buy something expensive and want to pay in installments. #1 and #5 allow no installment plans, naturally.

#2 is probably not very common yet.

Finally, I don't even know what #3 is. But I had to mention it since it was listed as a possible payment method on the website shown by the thread starter.