Impression Share is a key performance metric in digital advertising that measures the percentage of impressions your ads received compared to the total number of impressions they were eligible to receive. It represents your share of voice in the auction-based advertising landscape, particularly in search engine marketing and display advertising.
Impression share is calculated using the following formula:
Impression Share = (Impressions Received ÷ Total Eligible Impressions) × 100
For example, if your ad was shown 800 times but was eligible to be shown 1,000 times, your impression share would be 80%.
The percentage of impressions your ads received on the Search Network compared to the total number of impressions you could have received. This includes searches that exactly matched your keywords and searches that were variations of your keyword terms.
The percentage of impressions your ads received on the Google Display Network compared to the total number of impressions you could have received on sites where your ads appeared.
For Google Shopping campaigns, this metric shows the percentage of impressions your product ads received compared to the total impressions available for your products.
Several factors can limit your impression share:
Understanding impression share is crucial for several reasons:
Market Presence: It indicates how visible your brand is in your target market compared to competitors.
Growth Opportunity: Lower impression share often signals untapped potential for increased visibility and traffic.
Budget Optimization: Helps determine whether budget increases could drive meaningful growth.
Competitive Intelligence: Provides insights into market saturation and competitive dynamics.
While benchmarks vary by industry and campaign type, general guidelines include:
The most direct way to improve impression share is increasing your daily budget, allowing your ads to show more frequently throughout the day.
Raising bids can improve ad rank and increase eligibility for more auctions, though this must be balanced against cost-per-acquisition goals.
Improving ad relevance, landing page experience, and expected click-through rates can boost Quality Score and ad rank without necessarily increasing bids.
Broadening keyword targeting, audience segments, or geographic reach can increase the pool of eligible impressions.
Analyzing when your audience is most active and adjusting ad scheduling can help capture more relevant impressions.
Platforms typically provide additional metrics to understand why impression share is limited:
Understanding how impression share relates to other marketing measurement metrics:
Impression Share vs. Reach: While reach measures unique users exposed to your ads, impression share measures your competitive position in the available inventory.
Impression Share vs. SOV (Share of Voice): Impression share is a more precise, data-driven metric compared to traditional share of voice measurements.
Impression Share vs. Market Share: Impression share indicates advertising presence, while market share reflects actual business performance and sales.
Impression share analysis is valuable across various industries:
E-commerce: Understanding product visibility in Shopping campaigns and search results.
B2B Technology: Measuring thought leadership presence in professional networks and search.
Healthcare: Ensuring medical services reach patients searching for relevant treatments.
Financial Services: Competing effectively in high-value, regulated keyword spaces.
Several platforms and tools provide impression share data:
When optimizing for impression share, consider:
ROI Balance: Higher impression share doesn't always correlate with better return on investment.
Audience Quality: Focus on impression share within your target audience rather than broad market share.
Competitive Dynamics: Understanding when to compete aggressively versus when to focus on efficiency.
Attribution Models: How impression share improvements impact overall marketing attribution and customer journey analysis.
Impression share serves as a fundamental metric for understanding your advertising presence in the digital marketplace. By monitoring and optimizing impression share alongside other marketing measurement metrics, businesses can make informed decisions about budget allocation, competitive positioning, and growth opportunities. Regular analysis of impression share trends helps identify market changes, competitive threats, and optimization opportunities that drive long-term advertising success.
Lauri Potka is the Chief Operating Officer at Sellforte, with over 15 years of experience in Marketing Mix Modeling, marketing measurement, and media spend optimization. Before joining Sellforte, he worked as a management consultant at the Boston Consulting Group, advising some of the world’s largest advertisers on data-driven marketing optimization. Follow Lauri in LinkedIn, where he is one of the leading voices in MMM and marketing measurement.