It's a smart thing not to drive packages into Canada if you're the vendor, without doing a full declaration. The border guards get REALLY picky about that. When I worked for our family business, and would go down to the states to visit my mom's mom, they would ALWAYS ask me if I was bringing anything over. I never did, but I know that during the mail strike a few months ago, some small business owners just had to chance it. Similarly, marking as a gift when it's not - they check the return address to see if it sounds "businessy."