Yes, I've talked to at least one person who worked as a car salesperson for a while and is surprisingly intelligent for that job. Their take was essentially that for a lot of people the obvious salesmany tactics work. Moreover, they asserted that the people who they don't work on are also generally people where even more polite tactics often won't work on, so one isn't losing that much.

I don't know how much this applies to cars, but I'd suspect that this applies even more to spamming.

Whether this applies to the NLP people is probably to some extent whether the NLP people are trying to attract smart critical thinkers or trying to attract the general population. I don't know enough about their goals to accurately speculate.