Alexa also lists amazon.ca, google.ca, canada.ca, kijiji.ca, realtor.ca, (ebay.ca), walmart.ca, cbc.ca, bestbuy.ca, airbnb.ca, homedepot.ca, and several *.gc.ca sites.
In my experience, outside the USA many ccTLDs are commonly used – including the "domain hack" ones, in their own country.
It helps that .ca domains are not available for all. As an individual, you need to be a Canadian citizen or permanent resident to purchase one. For companies, they need to have presence in Canada.
Yeah, seriously. Spend any time in Europe. Most local websites are at their ccTLD.