A daily budget is the amount you set as the average daily spend for a Sponsored Products, Sponsored Brands or Sponsored Display campaign. Amazon treats it as an average rather than a hard cap: on a high-traffic day a campaign may spend up to 25% above its daily budget, provided total spend for the calendar month does not exceed the daily budget multiplied by the number of days. When a campaign has spent its available budget for the day, its ads stop until midnight in the marketplace's time zone, and the campaign shows as "out of budget."

Why it matters

Budget is the hidden cause of many traffic problems. A campaign that goes out of budget at 11 am has been invisible for the rest of the day, including the evening hours when many categories convert best, and its reports will show falling impressions and sales with no change to bids or listings. Amazon shows this in the campaign list, and the budget report estimates the sales missed.

Budgets are also how spend follows performance. Two campaigns with the same target and the same daily budget will not deserve the same money after a month; the one hitting target should get more of it and the one missing target less. Leaving budgets flat for months is one of the most common ways an account drifts.

What moves it

  • Bids and traffic, which decide how quickly the budget is consumed.
  • Budget rules, which Amazon offers to raise budgets automatically on schedules, for events or when performance meets a condition.
  • Portfolio budgets, which cap total spend across a set of campaigns and can stop them all at once.
  • Events. Prime Day and Black Friday can consume a normal day's budget in an hour.

How we use it

Budget utilization is checked weekly campaign by campaign. Campaigns that go out of budget with ACoS at or under target have budgets raised; campaigns that go out of budget above target have bids trimmed rather than budgets raised; campaigns spending below 90% of budget are checked for bid or eligibility problems. Event budgets are staged in advance with rules, so no campaign goes dark on the day it matters.