In the early days of companies trying to sell us stuff we don't want by flooding our mailboxes with junk mail "spam" the seller's goals were typically much simpler.
They weren't necessarily trying to scam us out of our paychecks, they were just trying to get people to choose their company over the competition, and felt direct advertising was the ticket to success.
Junk mail "spammers" used the postmasters to help them pass along their "important messages" to people in town, in a time when most people were delighted to find
For a variety of reasons, the first junk mail (targeted mail, generic mail . . . take your pick) went to and through local postmasters. Small town postmasters knew anybody and everybody in town, knew their businesses, knew their interests, knew their foibles. Much such mail was addressed directly to the postmaster, asking him to pass it along to someone in town likely to be interested in the product.
Dick Sheaff posted an interesting historical article on Ephemera Society about how Junk Mail Is Nothing New, which includes a couple dozen endearing examples of what junk mail looked like in the olden days.
-Via Boing Boing