My father, who's not a regular internetgoer, has on several occassions called to me about certain spam emails to verify with me if they're real or not and I wouldn't call my father an idiot. Some of these spam things can be quite convincing.
When scammers call on the phone, it's often the weakwilled (which doesnt mean stupid) and the elderly (who are often weakwilled) that get overwhelmed by the scammer to signing into the scam.
To those that aren't technically savvy and haven't grown up with the internet, scams like these can appear real and convincing.
I'm a bit of a weakwilled person when it comes to being confronted in person, so one door-to-door scammer got me once, because I was simply overwhelmed and incapable of reflecting on it until afterwards.
Scamming is an art and some people are really, really good at it. Others, not so good at it.