Budgets and limits

Three limits decide how much a campaign can spend: its daily budget, its total budget and your account balance. The engine checks all three before every auction win and again when it charges.

Daily budget

The most a campaign may spend in one day.

The daily budget resets at midnight in your account time zone. The field is optional: if you leave it empty, the campaign has no daily limit and is held back only by its total budget and your balance. The form summary shows No limit in that case. For a new campaign, setting a daily budget is strongly advised.

Total budget

Total budget (USD, optional) caps lifetime spend. Once the campaign has spent it, the campaign stops competing. Within a minute it is marked Completed, as it is when its end date passes. A completed campaign cannot be resumed; extend the end date or total budget on the edit page and it runs again. Leave it empty for no lifetime limit.

Balance

All campaigns spend from your one prepaid balance. When the balance cannot cover the next event, every campaign stops buying until you add funds. See Add funds.

How the checks work

Before a campaign wins a request, the engine checks that:

• your balance covers the cost of the event,
• today's spend plus that cost stays within the daily budget,
• lifetime spend plus that cost stays within the total budget.

For CPM, the cost is the price of one impression; for CPV, the price of one view. For CPC and CPA, the engine checks that the next click or conversion at your bid is still payable. If any check fails, the campaign is skipped and the next bidder is tried.

The charge itself is made again against the same limits at the moment of the event, so two requests cannot both spend the last cent.

When a budget runs out mid-flight

A few events can arrive after a limit is reached, because the ad was delivered before and rendered or converted after:

• CPM impression: if the budget or balance ran out between delivery and render, the impression is recorded at a cost of zero. You are not charged.
• CPC click: if the budget or balance cannot cover the click, it is recorded but not charged.
• CPA conversion: the postback is refused with the reason budget. The conversion is not recorded or charged, so your tracker can retry it after you add funds or raise the budget.

Other limits on spend

Field limits

Watching spend

The campaigns list at /app/advertiser/campaigns shows each campaign's bid, daily budget and amount spent, with your balance at the top. Reports at /app/advertiser/reports break cost down by date, country, zone and more.

To stop spending at once, select Pause on the campaign. Pausing takes effect immediately and does not need a review to resume.

Practical advice

• Set the daily budget to what you are prepared to lose on a test day, not what you hope to spend at scale.
• Use a total budget on tests so a forgotten campaign cannot keep spending.
• If a campaign spends its budget early in the day, use Share of eligible traffic or a frequency cap to slow it down rather than raising the budget.