Your mileage may definitely vary. In 20+ years, I’ve had four incidents of receiving obviously counterfeit goods; no idea if it has happened more often than that and I was just unaware.
Certainly fair! I suspect there's probably some concentration in particular product areas - would be interested to see any research done (though that'd be tricky, given the cost involved and the difficulty in proving something to be counterfeit)
Good point. I only have my own anecdata and that of friends; it would be nice to see some real stats. Of course, even if Amazon has that data, they would be unlikely to share!