What are Impression Share and Impression Rank in Rank Radar?

Impression Share (IS):
Impression Share indicates the percentage of shoppers who searched for a specific term and saw an ad for it.
Example: If your Sponsored Products ad has a 35% impression share for a search term over a given date range, it means the ad appeared 35% of the time when that term was searched. Keep in mind that while the ad appeared, it might not have been visible to shoppers if it was below the fold.

Impression Rank (IR):
Impression Rank is a numerical ranking of your account-wide PPC impression share compared to other advertisers for the same keyword.
Examples: If your impression rank is 3 for a keyword, two other advertisers have higher PPC impression shares for that term.

An impression rank of 1 means you have the highest PPC impression share for that keyword among all advertisers.

The Impression Share and Impression Rank metrics in Rank Radar are for Sponsored Products PPC Impressions. For instance, if your impression share is already close to 100%, raising the bid may not significantly impact your ad’s visibility.