I've heard that for many scams it's actually the opposite: They intentionally throw in huge warning flags so that the people who initially "bite" are less likely to have second thoughts later on, and thus the scammer wastes less time chasing false leads. They're basically prequalifying you as a good mark. (There is a good lesson about marketing here too — theoretically "perfect" copy or design may not be ideal for your market, so test and see what provides the best ROI.)

here's a source that says something similar: http://www.computerworld.com.au/article/428151/why_nigerian_...

The problem for the scammers is the response rate is too high. The scammer has to invest time into writing back to the target, so they don't want to spend all day writing letters back.

By peppering the letters with bad spelling, punctuation and case mistakes, they eliminate 99.5% of the population who correctly detect it as a scam. Thus, when they do get a response, the person is much more likely to convert.

It applies to startups if signing up the customer requires cost on the part of the startup. If, for whatever reason, you had to sign up a limited number of people and invest time in each of those people, then reducing your response rate by, say, making the signup process complicated, would allow you to pre-qualify your audience by those actually able to navigate their way through it.

It would have real applicability if you wanted to get a limited market for beta testing.

The poor spelling probably increases the conversion rate from people who make the first reply. The nigerian prince and poor-spelling spammers are dead giveaways to a spam. If you filter out people who know about these cliches, you increase the likelihood that the responder will give you money.

Could you imagine how many emails that they would have to field if they were, at a first pass, a convincing forgery? It's almost certainly used as a low pass filter to only prey on the ones likely to fall for it in the long run.

I read a theory (probably on this site) that using obviously terrible scams helps them select for the most gullible people - e.g. the kind who would wire $500 of their own money back to Nigeria when the laptop arrived and "didn't work", plus a few hundred to cover expenses.

They have already. I regularly get properly phrased phishing emails from "PayPal". A few times I even got some from the banks that I use. I'm not sure if it was a coincidence or not, but the only thing that gave it away was the phishy URL.

Those are different. Phishes strive for perfection, because they win as soon as you log in to the fake site.

These "long con" 419 scams need to rebuff intelligent/savvy people and only attract rubes.