Charges and your daily budget
Internet traffic is like an ocean. Some days, there will be small waves. Other days, there will be great big ones. So, if your ads don't show up much because of low traffic, then we'll make up for that by showing them more when traffic's higher.
That's why we allow up to 20% more clicks in a day than your daily budget allows. This is called overdelivery. And it's a good thing: if we end up showing your ad too much -- to the point where you accrue more costs than your daily budget allows for over a billing cycle -- then we'll give you a credit for those extra costs.
Overdelivery and your daily budget
As we mentioned, you might see that your advertising costs each day are a little higher or lower than what you set for your daily budget. If you do, don't worry -- over a month-long billing cycle, you won't be charged more than your daily budget would've allowed for over 30.4 days.
Let's explain that number.
Basically, 30.4 is the average number of days in a month (365 days in a year / 12 months = 30.417). Google multiplies your daily budget by this number so we know what your budget should be over the course of a month.
Let's say you set your budget at $5 a day and your billing cycle is 30 days. Over the course of the month, you notice that your charges vary. Some days you're charged $2, on others you're charged $7. But at the end of the month, your charges won't exceed $152 (that's 30.4 multiplied by your $5 budget). So even though your campaign costs tipped above and fell below your $5 budget from day to day, at the end of the month, you're still charged no more than what you budgeted.
The waves of Internet traffic might make your daily costs go up and down. But at the end of the month, despite those unpredictable waves, you'll find your costs at right where you expected them to be.
Check for overdelivery
Sometimes we deliver over your monthly budget. In those cases, we'll credit the overdelivery cost back. If you'd like to see whether we've given you overdelivery credits, follow these steps:
- Sign in to your AdWords account at http://adwords.google.com.
- Click the gear icon and choose Billing.
- On the table below, you'll see your transaction history.
- Click any Campaign activity link you see in your transaction history.
- Any credits for excess activity will appear in the Overdelivery credit field.
Want to view activity for a certain time period? Just click the All time box at the top right-hand side of the page. Then, choose whether you want a Detailed or Summary view in the gray toolbar.
- On automatic payments? Learn when you'll automatically be charged.