Fair Billing for the PRO plan of Podcast API

The PRO plan's pricing structure consists of two parts: a base fee US$180 and an overage fee (if any).

Previously (Dec. 2017 ~ Jan. 18, 2023), the base fee US$180 was mandatory even when 0 requests are used in a billing cycle (30 days).

From now on (Jan. 18, 2023 ~ now), the PRO plan subscribers will pay $0 if no any requests are used in a billing cycle (30 days). In other words, the base fee US$180 should be paid only when at least 1 requests are used in a billing cycle (30 days).