The starter of the chain is always the most profitable. The killer of the chain is the risk. The spamming of the audience is the work. The profit potential is 3.9M sats at 1k sats per chain name for each chain that goes 5 deep without interruption. But I don't think anyone is dumb enough to do it.
Discussion
To clarify the math:
Add your name to the top, take the 5th name off the bottom.
Each forwards to 5 people and with the same instructions
Would end up:
5
5x5
5x25
5x125
5x625
= Potential 3,905,000
Now, in reality, the same people would likely get spammed the same message and the we'd track down who the asshole is that started this mess and insta block.