Case for the sale of the book-constructor "Smack PP"

Customer Demand: Book Sale and Attracting New Subscribers

After discussing all the details, I developed a video-creative and text for advertising, and set up a advertising campaign.
Starting a cold audience for interests
Budget per day: $3
Advertising is 11 days.

The price of the book was not fixed, people paid as much as they thought it was necessary.

For the time of the advertising was spent $32
775 new subscribers
The price of one subscriber is 0.04$.
They sold 50+ books in the amount of 5042 UAH, which is 4 times covered by the advertising budget.