1 unit per 100 comments. Mining 5 videos at 300 each costs 15 units.
Idea bank
Stored only in this browser. Create one at Google Cloud → Credentials after enabling YouTube Data API v3, then restrict it by HTTP referrer. Add two entries so it works on every page load: https://viralgap.pages.dev/* and https://viralgap.pages.dev/
Quota
Google gives 10,000 units per key per day, resetting at midnight Pacific. This page counts what it spends and shows it on the Outliers tab. The count is per browser, so scans from your phone and laptop are tracked separately.