A PPC friend asked an interesting question today.
If you’re a PPC nerd like me, the answer might interest you.
I am going to paraphrase the question a bit to make it more concise:
“Could you explain to me why I have a 50% Impression Share and only a 35% Click Share in this campaign? I don’t understand how there can be such a significant difference.“
My answer:
“Here’s my understanding: let’s say Google gets 100 user queries for which your campaign is eligible (meaning, you entered the auction). IS of 50% means that your ad shows 50 times. BUT your ad is not the only ad. Your competitors also show. Click share of 35% means that you get 35% of all the clicks on all the ads in all 100 auctions that you entered.
So let’s say these 100 SERPs generated 60 clicks on ads total for Google, and you got 20 clicks out of your 50 impressions, your click share would be 20/60 = 33.3%.“
Some more theory with links to resources:
Impression share includes all auctions where your ad showed (impressions), and all auctions where your ad is competitive enough to enter the auction (total eligible impressions). Impression share (IS) is the percentage of impressions that your ads receive compared to the total number of impressions that your ads could get.
Impression share = impressions (50) / total eligible impressions (100), thus IS = 50%
Click share includes all auctions where your ad showed or where your ad was competitive in the auction but did not show. (total eligible impressions)
Let’s say that, during the day, all auctions where your ad is competitive enough to enter the auction generate a total of 60 clicks on the ads (note every single SERP view can generate 0 or more ad clicks). And let’s say you got 20 of those clicks.
Now you have:
Click share = 20/60 , thus 33.3%
More details:
https://support.google.com/google-ads/answer/6299696?hl=en
https://support.google.com/google-ads/answer/2497703?hl=en
– Nils