If you live in Canada and want to get started selling on Amazon, then I’d highly recommend you start selling on Amazon.com in the United States.
Amazon.com is the biggest market and has the most potential to make money as an Amazon seller.
Not only that but because of the benefits that the US dollar provides in comparison to the Canadian dollar, you’ll earn significantly more money.
Unfortunately, Amazon.ca just isn’t that big of a market and while you can still make decent money in Canada, the real potential to make things worthwhile will be on Amazon.com. You'd even want to consider selling in the European marketplaces before Canada, as there's also bigger demand there as well.