This document discusses search impression share, which refers to the percentage of available search impressions an advertiser receives through their ad placements. It focuses on Google's metrics for measuring impression share on the search network, including search impression share, search lost impression share due to budget, and search lost impression share due to rank. These three metrics together account for 100% of available impressions. The document delves into each metric and how advertisers can potentially improve impression share by optimizing budgets, bids, geographic targeting, and keyword selection, while noting that impression share does not necessarily indicate ad quality or performance.

1. Search Impression Share:
Myths & Realities
Pierre M. Fiorini, Ph.D.

2. Search Impression Share
• A lot of talk…”Share of the Voice”

3. “Share of Voice”
• Definition:
– Refers to the percentage of available impressions
that an advertiser will achieve through an ad
placement
– E.g., If an advertiser bought all available
impressions on a site (i.e., had an exclusive
sponsorship), they would achieve 100% share of
voice.

4. “Share of Voice”
• More specific…for an ad campaign…
SOV =
𝐴𝑑 𝐼𝑚𝑝𝑟𝑒𝑠𝑠𝑖𝑜𝑛𝑠 𝑦𝑜𝑢 𝑔𝑒𝑡
𝑇𝑜𝑡𝑎𝑙 𝐼𝑚𝑝𝑟𝑒𝑠𝑠𝑖𝑜𝑛𝑠 𝐴𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒
• Has been traditionally used in Display Ad
campaigns (and TV + Radio)

5. “Share of Voice”
• So, for example…
SOV =
60,000 𝐼𝑚𝑝𝑟
100,000 𝑇𝑜𝑡𝑎𝑙 𝐼𝑚𝑝𝑟
= 60%
• Here you would have 60% share of the voice

6. “Share of Voice” - Google
• Google AdWords (and BING + Yahoo) provide
similar measures…
• For PPC, 4 Basic Metrics
– Search Impression Share
– Search Lost (IS) Budget
– Search Lost (IS) Rank
– Search Exact Match (IS)
Will focus
on these

7. “Share of Voice” - Google
• For Display (GDN), there are similar metrics…
– Display Impression Share
– Display Lost (IS) Budget
– Display Lost (IS) Rank
• Will NOT focus on these – Interested in PPC

8. Impression Share – Deep Dive

9. Impression Share
Three metrics that work together and impact each other.
• Search impression share: Impressions received on the Search Network divided by the
estimated number of impressions that are eligible to serve ads.
• Search Lost IS (budget):The percentage of time that ads weren't shown on the Search
Network due to insufficient budget.
• Search Lost IS (rank):The percentage of time that ads weren't shown on the Search Network
due to lower Ad Rank in the auction.
IS + Lost IS (budget) + Lost IS (rank) = 100%

10. Search Impression Share – Deep Dive
• Impressions received on the Search Network divided by the
estimated number of impressions that are eligible to serve
ads.
• 70% or above as a good impression share. But remember that,
for a campaign which has 70% overall impression share, you
are still missing 30% of the available impressions.
• Impression share loss can happen because of the following:
– Due to Budget
– Due to Rank
– Due to Geos

11. Lost Impression Share (Budget) –Deep Dive
• This data shows how much impression share you are
missing; due to an insufficient budget (Limited by
Budget in the status column of the campaign table next
to your campaign is an indication of insufficient
budget).
– Increase your daily budget to improve your impression
share lost due to budget.
– Make sure the improved impression share is producing
positive results. The increased impression share should
bring in more quality clicks and conversions.

12. Lost Impression Share (Rank)
• This shows how much impression share you
are losing due to your low ad rank.
– Your ad rank depends on your Bid and Quality
Score (Ad rank = Bid Quality Score)
– So if you want to improve your impression share
due to poor ad rank, you should try to increase
your keyword bid and quality score.

13. Factors Impacting Search
Impression Share

14. Search Impression Share
• Major Factors Impacting IS…
– Geos
• Tighter geos improve Impr. Share
– Budgets
• Small budgets tend to have lower Impr. Share
• Large budgets tend to higher Impr. Share
– Position
• Higher positions lead to higher Impr. Share
• Lower position lead to lower Impr. Share

15. Impression Share –
Examples

16. Example…Improving IS
Available Impressions
Impression Share
Here, the
Impr. Share
is about
40% Given
this GEO
Radius
Targeted GEO

17. Example…Improving IS
Available Impressions
Impression Share
Just
Shrinking
GEO can
improve IS…
NOTE: Reach has
decreased! – Limit
available
impressions

18. Examples…
Adds up
to 100%

19. Impression Share –
Perceptions vs. Reality

20. Impression Share
Perception/Reality
• Perception
– Gives the advertiser an indication of how often they win auctions given bids + desired geos.
– Can help to identify lower quality keywords and campaigns.
– Can be interpreted as “Share of Voice”
– Advertisers may increase budgets to improve Impr. Share
• Reality
– Has be interpreted as “Share of Voice” – But, really indicates performance in auctions given bids + geos
– Lower Impr. Share does not mean “unqualified traffic” – could mean bidding in lower positions – thus, LOST IS (Rank)
would be high in this case and Impr. Share would be lower
– Can Influence the advertiser to increase bids to improve impr. Share, but results in higher CPA, less VDP’s, less website
traffic
– Push the advertiser to increase budgets just to get higher Impr. Share
– Advertisers have no control of other factors that are not published.
What we have found…

21. Impression Share
Approach
SUGGESTED GOAL: Try to get Impr. Share to 50%+
CTR: Eliminating lower CTR keywords improves impression share.
Geo-Targeting: Higher targeted geos improve impression share, but may increase
CPC.
Keyword selection: Using broad modifiers , exact match, fewer keywords improve
share

22. Thank You!!!
Questions???