A friend of mine who worked in spam years ago told me that one percent of the people who receive a spam email will open it, and one percent of those will respond. So if you send out 1,000,000 emails, 10,000 will be opened, and 100 will fall for it. Say you get each of them for $100...that's $10,000 for sending an email.
Not a scammer, but weirdly like one: DH and I just closed on our house (yay!). We're in the process of moving, but I'm working from home also. Yesterday the doorbell rang; I went down and there was a couple standing there. We all looked at each other for a minute, and I finally said, 'Can I help you?'. The man said, 'BJ is supposed to be here'. Who's BJ? Their realtor. I said, 'That's odd...we just closed on this house last week, it's no longer for sale'.
A few more minutes of confusion and a call to BJ, who was waiting at a different house on the same road, and we got sorted out. They had seen our house driving around, and had said to the realtor 'the first house on Main street, tan with brown trim'. That's our house if you enter Main street from the north. If you enter Main street from the south, the first house is also tan with brown trim. Since our house doesn't have a visible street number (yet), the realtor made an Assumption.
I'm sure it wasn't a scam, because a bit later I drove down Main street past the other tan house, and there they were, with a woman in a car with a realtor's sign on the side, and the tan house had a For Sale sign. Very confusing for a few minutes, though!