Your daily budget is the amount that you're willing to spend on a specific Ad Exchange campaign each day.
Ad Exchange displays your ads as often as possible while staying within your daily budget. When the budget limit is reached, your ads will typically stop showing for that day. How quickly your ads are shown during a given day is determined by your ad delivery setting.
On any single day, the system may deliver up to 20% more ads than your daily budget calls for. This helps make up for other days within the same billing period in which your daily budget is not reached. (Days in which your daily budget is not reached may include partially paused days.) However, our system makes sure that in a given billing period, you're never charged more than the number of days in that billing period times your daily budget. For example, if you budget US$10 per day, and you're charged for a 30-day billing period, the maximum you would pay is US$300.
Learn how to change a campaign's daily budget.