Impression share is a metric used in online advertising that represents the percentage of impressions an advertiser receives out of the total available impressions in a specific market or target audience. It provides insights into the level of exposure and visibility an advertiser achieves compared to their potential reach. 

Some key points 

  1. Definition: Impression share is the ratio of the number of impressions an advertiser’s ad receives to the total number of impressions available for the selected targeting criteria, such as keywords, placements, or audience segments. It is typically expressed as a percentage. 
  2. Market Coverage: Impression share helps advertisers understand how effectively their ads are reaching their target audience within a particular market or advertising platform. A higher impression share indicates that an advertiser’s ads are being displayed more frequently relative to the competition. 
  3. Ad Rank and Position: Impression share is influenced by factors such as ad rank, bid strategy, quality score, and budget allocation. Advertisers with higher ad ranks and budgets are more likely to achieve a higher impression share and secure better ad positions. 
  4. Competitor Analysis: By monitoring impression share, advertisers can assess their performance relative to competitors. It provides insights into market competitiveness and opportunities for improving ad strategy and budget allocation. 
  5. Lost Impression Share: Lost impression share is the portion of available impressions that an advertiser did not receive due to various reasons, such as budget constraints, low ad rank, or targeting limitations. Identifying the reasons behind lost impression share can guide optimization efforts and help prioritize budget adjustments or campaign enhancements. 
  6. Share of Voice: Impression share is often used as a proxy for share of voice, which represents the visibility and dominance of an advertiser’s brand or messaging in the market. A higher impression share indicates a larger share of voice and increased exposure to the target audience. 
  7. Optimization and Growth: Tracking impression share over time allows advertisers to evaluate the effectiveness of their optimization efforts and measure growth in market presence. Incremental improvements in impression share can lead to increased brand awareness, website traffic, and conversions. 

Impression share is a valuable metric for advertisers to gauge their level of exposure and visibility in the online advertising landscape. By monitoring and optimizing impression share, advertisers can improve their market coverage, compete more effectively, and increase the reach and impact of their advertising campaigns.