This document discusses key concepts related to costs and pricing in telecommunications markets. It distinguishes telecom as a true "network industry" due to network effects, where adding new customers benefits both those customers and existing customers. This influences policies like universal service and interconnection requirements. Regulatory policy must account for network effects and competition. Telecom costs are largely fixed, with minimal variable costs for usage. Efficient pricing would be a simple flat monthly fee, but demand factors require alternative pricing structures. The document also discusses concepts like standalone costs, traffic-sensitive vs. non-traffic-sensitive costs, and how price discrimination can be used to improve industry performance without extensive price regulation.