This type of action is normally considered an illegal pyramid scheme or illegal chain letters and may result, as the US Postal service is used, in a person committing federal mail fraud. See here and here.
If you read the second link I provided, this one here, it discusses the illegality of a pyramid scheme, which is basically a scheme that requires others to join it so that money flows in to those already involved. Whether one asks to have their name added or whether one asks others to pay to be on such a list, the basic foundations of a chain letter/pyramid scheme are still in place and it will be illegal the same. These articles discuss this further: here here here
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