The Nigerian prince scam has been going on since Al Gore invented the internet because of 1 reason - it works. Some years ago, a guy from here in Idaho fell for it. He even went to Nigeria to get his money. He got very lucky. He only lost about $5k and he got home alive and healthy. Others haven't been that lucky.
I worked for a brokerage firm where one the the VP got taken for over $250,000. Even after the head of our fraud department sat him down and told him what was happening he continued to send money.