Glossary
What is Search lost top IS (rank)?
Melvin Salas1 min readVerified 9 October 2026
Short answer
Google's definition: Search lost top impression share (rank) estimates how often your ad didn't show anywhere among top ads due to poor Ad Rank. Its partner column, Search lost top IS (budget), covers how often Google puts the same miss down to a low budget. Our reading: the column does not say whether the ad showed lower on the page or did not show at all. It does not separate the two.
It is a different column from Search lost IS (rank), which Google defines as the percentage of time that your ads weren't shown on the Search Network due to poor Ad Rank in the auction. Our reading: one is about showing at all, and this one is about showing among top ads, and the two are measured differently, so one can be low while the other is high.
Ad Rank has more than one input. Google says it considers ad quality in establishing your Ad Rank, and that the amount you bid may affect your Ad Rank but doesn't impact the assessment of your ad quality. Our reading: a rank loss is not only a bid problem, and the column on its own does not say which input to change.
Google's general tips for improving impression share include increasing your bid, which it says can improve the likelihood that your ad will show for a given ad auction, and, for Search Network campaigns, improving your ad quality. Our reading: those tips are a general list for impression share, not a prescription Google attaches to this column.
The stricter version is Search lost abs. top IS (rank), which Google says estimates how often your ad wasn't the very first ad among top ads due to poor Ad Rank. Search partners don't distinguish between 'top' and 'others' and 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.