In Canada it is preferable to buy both extensions (if available). Canadians may shop .ca due to cross-border restrictions and consumer confidence. Many still prefer dot com though most good dot com's are long gone.
Federal policy and taxation, regulated on a provincial level. With a bottleneck of red tape, many growers remain in the shadows. Having a steady flow of customers in dispensaries and head shops, online stores popping up. Will be a huge demand for public education, health and medical, professional career development etc.
Next year we'll see an emergence and likely more demand for .ca as the industry defines itself.