Tiered Pricing in BillingPlatform allows you to create products that can be priced differently depending on the quantity being rated for the customer. This is particularly useful in products and bundles that is charged to the customer at a lower rate the more usage they accumulate or the bigger the quantity purchased.
For example, you have a product called Talk Time that you charge the customer a certain rate per minute. Now, let's say you charge a customer who uses 0 - 100 minutes at 0.10 per minute. Then, anything in excess of 100 minutes is rated less, at 0.05. In this case, you create a single product but with tiered pricing, one rate for 0 - 100 units of usage and another if usage goes beyond 100.
Refer to the How To link below on how to configure your tiered pricing product.