1. Active, not passive: This is income made by actively promoting the book upon its release as stated in the post. 2. Past, not future: This is historical reve

1. Active, not passive: This is income made by actively promoting the book upon its release as stated in the post. 2. Past, not future: This is historical revenue based on active marketing. It is unlikely that it will bring the same income in the future without marketing. 3. Revenue, not profit: The nice cover design is something others would need to pay for if this is to serve as reference, but this cost isn't taken into account. TLDR: He isn't making $400 ($360) in passive monthly income and it is unlikely he will in the future.