[gojomo]

I also found it surprising that scammers devote so little effort to proper spelling/punctuation/grammar.

But then it occured to me: maybe errors help filter out attentive respondents, who have a low chance of completing the whole scam funnel. Those people who don't notice the errors, or don't consider them a red flag, are better leads.

In the context of a cliche'd Nigerian origin, sure, mentioning Nigeria puts anyone familiar with the 419 scam formula on guard. But anyone who does reply is likely a fresh, naive prospect. Ka-ching!

[lurker19]

This is perceptive. 419 is like any other advertising: if you think it is stupid, you are not in the target market, but someone else is.

Who communicates in all caps? The elderly and the mentally ill. Target market.