Glossary
What is Search lost top IS (budget)?
Melvin Salas1 min readVerified 9 October 2026
Short answer
Google's definition: Search lost top impression share (budget) helps you to understand how often your ad didn't show anywhere among top ads due to a low budget. It is the budget side of a shortfall in Search top IS. Its partner, Search lost top IS (rank), estimates how often the same shortfall was due to poor Ad Rank.
It is not Search lost IS (budget), which Google defines as the percentage of time that your ads weren't shown on the Search Network due to insufficient budget, and says is available at the campaign level only. Our reading: that column is about showing at all, and this one is about showing among top ads.
Google's general tips for improving impression share start with increasing your campaign budget, and say your budget controls how often an ad is shown. Our reading: the tip is written for impression share in general. Google does not attach it to this column, so read the column as naming the constraint Google measured rather than as an instruction.
Be careful with the budget tips Google gives under the heading for improving absolute top impression share. That section describes absolute top impression share for Shopping campaigns and Hotel campaigns, so it is not a statement about a Search campaign's top of page position.
The stricter column is Search lost absolute top impression share (budget), which Google says estimates how often your ad wasn't the very first ad among top ads due to a low budget. Search partners won't be included in impression share data, Google notes.
Reading these columns is daily work for us
Riibon watches every campaign daily and holds a baseline for each metric, so a move in impression share or Quality Score is judged against what is normal for that account, not against a rule of thumb, before anyone acts on it.
Ask the Riibon app whether your campaigns are losing to budget or to rank. It is free, with no time limit and no card. Or book a call and we run it for you.