We have a free tier and a paid one. For free users, we keep 25% of all sales transactions. The Pro tier costs US$19.99 per month or US$200 per year. For Pro users, we charge 10% of digital sales and 25% of net physical sales. Net sales are defined as follows – if you price your book at US$10 and the print cost is US$3, then you keep 75% × (10 − 3). Shipping is paid by each fan according to their location, as are any local taxes.