The method, the arithmetic, and the honest limits.
Google grants 10,000 units per key per day, resetting at midnight Pacific. A typical four-pass scan costs roughly 450 to 900 units depending on how many channels survive filtering, so a working day holds somewhere between eleven and twenty full scans. The meter on the scanner counts every unit as it is spent, and calls that Google rejects before metering are refunded.
Erratic channels. If more than a quarter of a channel's catalogue beats its own median, that median is not describing a normal upload — it usually means the channel posts mostly duds with occasional hits. Those channels are flagged so you can discount their multipliers, or hidden entirely.
Off-topic uploads. A channel's upload feed contains vlogs, announcements and unrelated experiments. The relevance filter requires the title to mention your niche, which stops a channel update with freak view numbers being presented as a niche insight.
Too-new videos. Videos under a week old have unstable views-per-day figures, so they are excluded by default. You can lower the threshold if you want the earliest possible signal and accept more noise.
Click-through rate, audience retention, impressions and revenue are visible only to the channel owner through YouTube Studio. No public API exposes them for other people's channels. Any tool showing you a competitor's CTR is modelling it from public numbers, and the model is a guess. findbangers reports only what is genuinely public and says so rather than inventing precision it does not have.
The API key lives in your browser's local storage and is sent only to googleapis.com. There is no account, no server storing your scans, and no analytics on what you search for. Saved ideas stay in your browser until you export them.