每日预算

每日预算是指您每天愿意为某个广告活动花费的金额。

每日预算金额按一个日历月期间的平均值计算。在任意一天，您的支出可以低于每日预算，也可以比平均每日预算多出最高 10%。这种机制让您能够从流量较高的日期受益。

到月底，您的支出不会超过您设置的每日预算乘以当月的天数。您的发票将针对任何超额投放进行调整，这样您支付的金额就不会超过每月收费限额。

当您的广告活动达到每日预算时，我们会通知您。

例如，如果您的预算为 $100，并且您在第一天收到价值 $90 的点击量，则您在第二天最多可以收到价值 $110 的点击量。这将使您在两天的总支出达到 $200，也就是平均每天 $100。

更改每日预算

您可以随时更改每日预算，所做调整将立即在您的广告活动中生效。在管理广告视图中，点击预算列中的预算金额并输入新的金额。您也可以通过点击广告活动名称并选择广告活动设置来更改每日预算。

如果您每天多次更改预算，您的最大广告活动支出将是当天有效的最高预算。如果您减少了每日预算，并且您的广告活动支出低于您的新预算金额，我们将以当天的新预算为准。如果您减少了每日预算，并且您的费用已经超过了新预算的金额，则您的支出将受到限制，新预算将在第二天生效。例如，如果您在中午将每日预算从 $100 更改为 $50，但您的广告活动在当天已花费 $80，那么您将需要支付 $80。如果您未做出进一步的更改，那么从第二天开始，您的每日预算将是 $50。

如果您在月中更改每日预算，当月剩余时间的广告活动支出不会超过新的每日预算乘以当月剩余天数所得的值。例如，您将广告活动的每日预算设置为 $50，并且截至该月 20 日，您在该月花费了 $800。在该月 20 日，您将每日预算更改为 $10。您将在该月支付的最高费用将是 $800（您到目前为止花费的费用）+ $110（$10/天 X 该月剩余的 11 天）= $910。

设置每日预算上限

商品推广每日预算上限是一个可选设置，用于控制所有在活跃状态下的商品推广活动每天总共可花费的金额。您可以在广告活动管理的广告设置选项卡下访问此设置。如果您不确定为商品推广活动设置多少每日预算，可以将此部分留空，并为每个广告活动设置一个单独的预算。

您还可以选择为品牌推广活动使用生命周期预算。设置广告活动时，一旦选择每日预算或生命周期预算，您将无法在两者之间进行切换。要更改品牌推广的预算编制方法，请复制您的广告活动并创建一个新广告活动。

 亚马逊官网原文详情：

Daily budget

The daily budget is the amount you are willing to spend on a campaign each day.

The daily budget amount is averaged over the course of a calendar month. On any given day you could spend less than your daily budget, or up to 10% more than your average daily budget. This system allows you to benefit from high traffic days.

At the end of the month you will not spend more than the daily budget you’ve set, multiplied by the number of days in that month. Your invoice will be adjusted for any over-delivery, so that you will not be charged for any amount in excess of your monthly charging limit.

We'll notify you when your campaign reaches its daily budget.

For example, if your budget is $100 and you receive $90 worth of clicks on the first day, you could receive up to $110 worth of clicks on the second day. This would bring your total spend over two days to $200, which averages to $100 per day.

Changing your daily budget

You can change your daily budget at any time and the adjustments will take effect immediately in your campaign. From the Manage Advertising view, click the budget amount in the Budget column and enter a new amount. You can also change the daily budget by clicking the campaign name and selecting Campaign Settings.

If you change your budget multiple times a day, your maximum campaign spend will be the highest budget in effect for that day. If you reduce your daily budget and your campaign spend is less than your new budget, we will enforce the new budget for that day. If you reduce your daily budget and you’ve already exceeded the new budget, your spending will be capped, and the new budget will take effect the next day. For example, if you change your daily budget from $100 to $50 at noon, but your campaign has already spent $80 that day, then you will be charged $80. If you make no further changes, then from the next day, your daily budget will be $50.

When you change your daily budget mid-month, campaign spend for the rest of the month will not exceed your new daily budget multiplied by the remaining days in the month. For example, you set a daily budget for your campaign to $50, and as of the 20th of the month, you’ve spent $800 in that month. On the 20th of that month, you change your daily budget to $10. The maximum you’ll be charged for that month, will be $800 (that you spent so far) + $110 ($10/day X 11 days remaining in the month) = $910.

Setting daily budget caps

The Sponsored Products daily budget cap is an optional setting that controls how much all of your active Sponsored Products campaigns can spend per day in aggregate. You can access this setting under the Advertising Settings tab in Campaign Manager. If you are not sure what to set for a daily budget across Sponsored Products campaigns, then you can leave this blank and set a separate budget for each campaign.

You also have the option to use a lifetime budget for Sponsored Brands campaigns. You can't switch between a daily budget and a lifetime budget after you have selected one when setting up a campaign. To change your budgeting method for a Sponsored Brand, copy your campaign and create a new one.

 文章来源：亚马逊官方网站