One bottle of 5× Mushroom Essence.
Three levels of word of mouth.
Mei buys a bottle
$5 comes straight back to her.
She shares with 3 friends
Each one orders, and Mei earns $15.
They tell colleagues
Mei earns $5 on each sale, up to three levels.
100 bottles a month
That's $500 a month. At 500 bottles, $2,500.
Illustrative example.