Basically, when a person has no proper awareness of what's going on with online society, they're more prone to scam.
I think some people from developing countries are in this group. Maybe they see the online world still like we looked at it 10 years ago, but then with all the threats of today.
What if you are poor, and suddenly people promise you free money online? Wouldn't you be tempted to try that? Especially if you are uneducated about online dangers? Or if English is your third language, and you have limited understanding only?