Sure. I'll try to explain how this works with enough detail so it makes sense to everyone.
Basically the credit card and address validation that Hulu does works like this:
#1. They compare the billing street address to the zip code to ensure that the the address is within the given zip code.
#2. They compare the zip code with the credit card's billing address to ensure that the zip code is the same one used on your CC billing address (i.e. the address your bank knows about).
Check #1 is easy to satisfy if you just lookup an address for a given zip code. The real question is how do you pick a zip code that matches your credit card? Your Canadian credit card doesn't even have a zip code! This is where we can take advantage of a feature in the credit card validation code run by credit card companies.
Have you ever been driving a rental car in the US, and before you return it you go to gas it up. You try and pay at the pump with your Canadian credit card (why not, your CC works everywhere else in the US) but then you encounter a problem. To validate that the credit card you are using is yours they ask not for your PIN number, but your ZIP code that is associated with the billing address of your credit card. Initially I thought that meant I just couldn't use my Canadian credit card in the US for those gas stations that did zip code validation. I later learned that there is actually a way for Canadian customers to satisfy the zip code question.
To prove that the credit card is yours, just take your postal code and strip out all the letters and enter the numbers. You'll only get 3 numbers from your postal code (my three numbers are 706) and you can have any two numbers after those three - and it will satisfy the zip code validation. So, in my case any zip code from 70600 to 70699 will work with the credit card validation algorithm. This "back door" in VISA validation was created specifically for foreigners who find themselves in the US and get prompted for their billing address "zip code", but it works pretty much everywhere since it is the same code on VISAs computers that validates the card on Hulu as it does for the gas station.
But while 70600 will satisfy the VISA validation check (item #2), that zip code won't satisfy item #1 because it is not a valid ZIP code, there are no addresses in that zip code. So, I try Googling 70601. A few more searches on Google and I've located a PO Box that has the zip code 70601 and I use that address as my billing address. Now I can satisfy checks #1 and #2.
#1. The PO Box address is indeed within the given ZIP code (they probably check some USPS web service for this).
#2. The ZIP code matches the billing address on your Canadian credit card (due to the back door which was created to allow Canadians to pay-at-the-pump to fill up their rental).