1 - 4 subscribers:   0% volume discount

                         5 - 9 subscribers:   5% volume discount

                        10-19 subscribers: 10% volume discount

                        20-29 subscribers: 15% volume discount

                        30-39 subscribers: 20% volume discount

                        40-49 subscribers: 25% volume discount

                        50-59 subscribers: 30% volume discount

                        60-69 subscribers: 35% volume discount

                        70-79 subscribers: 40% volume discount

                        80-89 subscribers: 45% volume discount

                        90 and more subscribers: 50% volume discount