The mechanics
Ad spend is charged on Google’s billing cycle. Revenue arrives on your payment processor’s payout schedule, minus refunds and chargebacks. Stock is bought before either.
Where it bites
Scaling fast means the spend increases immediately and the corresponding revenue lands later. A profitable account can still drain the bank in the month it grows.
What to do
- Model the gap before you scale, not after.
- Scale in steps so the gap grows gradually.
- Watch refund rate — it hits cash twice.
This is also why we invoice weekly rather than monthly: it keeps our fee proportional to what actually happened, not to a forecast.