I never respond about someone who i don't know PM me and offer something, any PMs i wouldn't ever to respond. I think people should do that because scammers will use a lot of ways to steal money from us. And something like what OP tell to us wouldn't harm anyone if people can ignore it. Glad for OP he is not easily believe to something like that.
the scammers will certainly do many ways to find people who are easy to get hooked and we must understand it. it's good indeed to forget and ignore things that are not clear, especially on offers that do not go in to what I think is potentially fraudulent. nowadays many methods are done by fraudsters, including sending PM or can also be via email but email will usually be more organized.
It should be the reason why we have to be cautious and attentive when it comes to emails because we can't literally assure that their intention was good. Also, scammers these days will always look for opportunity to deceive us even if we tried to protect and secured our funds by not believing into their words and promises particularly when you have seen that it is quite difficult to fulfill. They will surely take advantage of you if they get the chance and that is why you have to open your mind when it comes to these kind of problem because you will never know when you will encounter it. It is also the reason why researching is always recommended because it can help you identify and determine if something is legit, it can help you make the right decision.