Canadian Incorporating in US
Do I have to have a physical address in the US or a US citizen as a partner to register a Corp?
It would make sense to register a company in the US if it would help your business, for example by making it easier for your US clients to pay you for your product, or if you want to establish a distribution center for your product in the US.
To register a US company you don't need to have a US address or a US partner, but having either wouldn't hurt. You can start by getting a reasonably cheap virtual office or mailing address.