Shared budgets allow you to allocate budget on multiple campaigns. If you have set a budget for your AdWords marketing ads, consider using a shared budget instead of setting individual budgets for each campaign. When you use a shared budget, AdWords can automatically adjust the allocation of spend to the various campaigns to help you to improve your return on investment . You can always revert to individual budgets to have more control over what you spend for each campaign.
A shared budget is ideal if you do not have the time to monitor the budget for each campaign, but you still want to get the most possible clicks from your ads within a defined budget.
Suppose you set a daily budget of EUR 100, divided equally between two campaigns. At a given day, a campaign can receive fewer impressions and clicks than usual, and you will then spend 40 EUR. With a shared budget, AdWords can use remaining EUR 10 and allocate it to the second campaign to maximize your overall performance.
Define a shared budget
You can always change your shared budget on the shared library page.
Change budget during the day
If, during the day, you decide to go from a individual campaign budget to a shared budget or vice versa, AdWords will start running your ads from the time you make the change.
Imagine that you have four campaigns, each with a budget of 6 EUR. At 3pm, each campaign has reached the limit of 6 EUR. At 4pm, you decide to create a shared budget amount of € 24 for the four campaigns. Your budget will be shared with an effective budget amount of EUR 24, as if the EUR 6 per campaign had not been spent.
Delete a shared budget
Each AdWords campaign have to have a budget, you can not delete a shared budget only if it is used by any campaign.
To remove a shared budget for your campaigns, follow these steps: