Google’s AdWords has released a new feature that will let an advertiser share daily budgets between multiple campaigns in a single account. The idea is that a marketer may have a set daily budget to spend across multiple product lines, or channels, and this feature lets them dynamically reallocate that budget if one campaign falls short on volume, for example.

The shared budgets feature lives in the “Shared library” section under Budgets. There’s a fairly elaborate graphic that explains how to use the feature.

If you switch to using a shared budget in the middle of the day, the new budget number will apply from the time you create it, as if $0 had previously been spent that day.

While some users responded positively to the new feature, others weren’t as enthusiastic. Marketers like Matthew Umbro, director of paid search at Exclusive Concepts, is concerned that, when the feature is used, one campaign will monopolize the others. “For example, Campaign A might contain more competitive keywords than Campaign B. Due to the high search volume of Campaign A’s keywords, the keywords in Campaign B won’t get the impression share necessary to gather enough data. Campaign A is not only using all of its own budget, but Campaign B’s as well,” he said. “Though a nice idea, I’m not sure how Google will regulate the impression share by campaign when advertisers utilize shared budgets.”