SevenCubed - 8:39 pm on Aug 29, 2013 (gmt 0)
From my many years of implementing both .ca and .com for Ontario based local businesses where I am physically located I haven't seen any downside or upside to either. It's really just personal preference.
I'm rather surprised that your friend insists that her visitors come via google.com though. Most casual searchers will simply be redirected back to google.ca if they tried to use google.com. They would have to be technically literate to bypass it -- something the average search engine users are not.
On occasion I grep numerous raw logs from various domains under my control for google.ca vs goolge.com for traffic referrals and .ca wins by 95%+
As for trust, .com vs .ca in results -- makes no difference to me and probably not to most average searchers either.
The only thing I can point out that is an advantage of having .ca is the WHOIS info is private by default as per CIRA practices. So you'll save the 5 bucks per years that so many registrars heap on to make you pay for privacy -- squeezing every last drop of blood out of a stone.