Emails you when an account's spend and impressions both suddenly collapse to near zero during a time it's normally active. This is your fastest signal that serving has stopped account-wide - whether it's a billing failure or a suspension - so you can jump on it straight away and get the account back live.
Why both signals?
Requiring spend and impressions to collapse together is what makes this reliable. Impressions alone can dip on a quiet day; spend alone can dip when CPCs fall. Both hitting near zero at a normally-active hour means serving has actually stopped.
Defaults & settings
Counts as dark when below - how close to zero both must drop, versus what the account would normally have done by this time of day. Default 5% of normal, adjustable 1-25%.
Baseline window (days) - how many trailing complete days build the median daily baseline. Default 14d, adjustable 3-30.
Checks every 30 minutes; 12-hour cooldown - so a continuing outage resurfaces.
