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.