What is Display lost IS (budget)?

The column is labelled Display lost IS (budget) in the interface, and Google’s definition is “the percentage of time that your ads weren’t shown on the Display Network due to insufficient budget”. Read that as written: the unit is time, the network is Display, and the loss is attributed to budget. Display impression share, a separate column, is defined differently, as the impressions you received on the Display Network divided by the estimated number of impressions you were eligible to receive. One is a ratio of impressions and the other is a percentage of time, and Google does not state that they add up to anything.

It is not the Search column with a different label. Search lost IS (budget) is defined the same way for the Search Network, and Google reports impression share metrics separately for each campaign type rather than aggregating them across the account. So a Display campaign losing a large share of its time to budget is not a reading of whether a Search campaign in the same account is budget limited, and Google does not add or average the two into one account level figure.

Where you can see it matters. Google makes the column available at campaign level only. In report editor it is available in the Campaigns report but not the Ad group report, and as of June 2022 Google removed it from any previously saved report that also used Ad group, Search keyword or Label (Ad group). A saved report that once showed the column and now does not has lost the column, not the budget constraint. The absence says nothing about the campaign.

Google’s guidance on improving impression share lists increasing the campaign budget, noting that your budget controls how often an ad is shown, and for Display campaigns adds improving display ad quality and adjusting managed placements. It does not map any of these levers to a particular loss column. If you add placements, Google says to consider re-adjusting the budget to cover the costs of the new settings. It also warns that if you remove placements, impression share may rise while the size of the “pie” has been reduced. In general, Google estimates eligible impressions from factors including targeting settings, approval statuses and quality, and says small fluctuations do not necessarily mean action is needed. So read Display impression share beside the absolute impression count, and after a targeting change allow that the pool may have moved as well as the share.

What Riibon does with it. Riibon’s daily campaign vitals read three impression share columns, all of them Search: Search impression share, Search lost IS (budget) and Search lost IS (rank). The Display column is a separate field, so any report built only on the Search fields has nothing to say about a Display campaign’s budget, and a blank there means the column was not read, not that no budget was lost. When Riibon’s campaign vitals roll a loss column up across days, they do not take a plain average of the percentages. Each measured day is weighted by its estimated eligible impressions, impressions divided by impression share, so a three impression day does not count as much as a three thousand impression day, and a window with no measured day returns no figure rather than an invented mean.