How does pothi.com earn money?

After the author specifies his/her earning on the book, we add our margin to it. This depends on the author's margin. Currently it is equal to the authors margin or a minimum. The minimum margin is 30% of the production cost with an upper limit of 30 Rs. What this means is that if the production cost is less than 100 Rs, the minimum margin is 30% of the production cost. For the production cost of 100 Rs. and above, the minimum margins is 30 Rs. If the cost of production is 60 Rs. for example, our minimum margin would be 18 Rs. If the cost of production is 200 Rs. our minimum margin would be 30 Rs.