How to Optimize Search Ads in Google Ads: Reduce Lost Rank and Increase Impression Share

There are many ways to optimize Search Ads in Google Ads, but two key metrics that many advertisers focus on are Impression Share and Lost Rank. We received a request to cover this topic, so we’re taking this opportunity to break it down for you in a way that’s easy to understand.

First, Let’s Understand Impression Share and Lost Rank in Google Ads

What is Search Impression Share?

Search Impression Share (or simply Impression Share) is the percentage of impressions your ads received compared to the total number of impressions they were eligible to get.

The formula is:

Search Impression Share = (Actual Impressions / Total Eligible Impressions) * 100

Simply put, it tells you how often your ads are showing up to your target audience. If your Impression Share is 100%, it means your ads are shown every single time a relevant search occurs (which is very rare in reality). If your Impression Share is 50%, it means your ads are showing for half of the eligible searches. The other half might be missed due to an insufficient budget or your bids not being competitive enough.

What is Search Lost Impression Share (Rank)?

Search Lost Impression Share (Rank), or “Lost Rank,” tells you the percentage of time your ads weren’t shown due to a poor Ad Rank. When your Ad Rank is too low, you lose out to competitors, and your ad gets pushed to other pages instead of appearing on the first page. This can happen for several reasons.

This metric is shown as a percentage. For example, if your Lost Rank is 30%, it means you lost 30% of potential impressions because your ad’s ranking wasn’t good enough.

How to Optimize Search Ads by Improving Impression Share

Increase Your Daily Budget

This is the simplest and most direct method. Impression Share is directly affected by your budget (you can also check the “Lost IS (budget)” metric). If your budget is too low, your ads won’t be shown as often.

A simple way to check if your budget is sufficient is to look at the “Lost IS (budget)” percentage. If it’s high, increasing your budget will help. Another way is to view a single day’s performance. If your campaign stops running midway through the day instead of spending consistently, it’s a clear sign your budget is running out too early. Increasing the daily budget for that campaign will directly address the problem.

Change Your Bidding Strategy to “Target Impression Share”

This is another straightforward solution. The Target Impression Share bidding strategy is designed specifically to solve the problem of low impression share, even with the same budget.

You can set this in your Campaign settings under “Bidding.” You’ll have a few options for ad placement:

• Anywhere on results page: Your ad can appear anywhere on the search results page.
• Top of results page: Aims to place your ad in the top positions (usually 1-4).
• Absolute top of results page: Aims for the very first position.

Then, you set the percentage of impressions you want to target. It’s best to look at your past performance first. For example, if your current Impression Share is 20%, you could try setting a target of 30-50%. You can always adjust it again after the campaign has been running for a week or two.

Refine Your Keywords

Remove keywords that are not performing well. Many people think that adding a large number of keywords is a good strategy to get more impressions. In reality, adding too many irrelevant or low-relevance keywords can cause your ads not to show. This is because the connection between your keywords, ad copy, and landing page becomes very weak.

Low-performing keywords with high search volume can dramatically decrease your Impression Share. Therefore, you should regularly review your keywords. Pause or remove any that have a very low Click-Through Rate (CTR) or are not directly relevant to your business. Focusing only on relevant keywords will help increase your Impression Share.

How Can You Optimize Search Ads to Address Lost Rank?

The approach here depends on your bidding strategy.

For Manual CPC / Maximize Clicks

If you’re using Manual CPC or Maximize Clicks, simply try increasing your CPC bids. When you set a higher maximum CPC, you’re telling Google you’re willing to pay more to compete, which helps your ad rank higher and not get lost in the auction.

For Maximize Conversions

If you’re using Maximize Conversions, you can try increasing your Target CPA (Cost Per Acquisition). When you set a very low Target CPA, the system becomes very selective, lowering your CPC bids to only show ads to users most likely to convert. This often leads to a lower Impression Share. By increasing your Target CPA, you give the system more flexibility to bid higher, show your ad more often, and compete more aggressively. This may increase your CPA, but it will also indirectly boost your Impression Share.

For Maximize Conversion Value

Similarly, if you’re using Maximize Conversion Value, you should consider lowering your Target ROAS (Return On Ad Spend). A lower ROAS target allows the system to bid more aggressively (higher CPCs) to capture conversions, even if they come from less valuable purchases. This increased competitiveness helps your ad show more frequently, thus improving your Impression Share.

Methods That Improve Both Impression Share and Lost Rank

Improve Your Quality Score

Improving your Quality Score is not a quick fix, as it involves several factors, but it’s one of the most effective long-term strategies.

• Ad Relevance: Ensure your ad copy includes your target keywords. If your keywords are too varied, organize them into tighter Ad Groups.
• Landing Page Experience: Your website must provide a good user experience. This means fast loading times and content that is highly relevant to both the keywords and the ad copy.
• Expected CTR (Click-Through Rate): A high CTR signals to Google that your ad is relevant and helpful to users. You can boost CTR by using strong calls-to-action in your ads, such as “Click Here,” “Free Consultation,” or “View Promotions.”

Maximize Ad Assets (Formerly Ad Extensions)

Adding Ad Assets is a free and easy way to make your ads more compelling. Assets like sitelinks, callouts, and images make your ad take up more space on the results page, making it more noticeable. This significantly increases your CTR. As mentioned above, a higher CTR leads to a better Quality Score, creating a positive feedback loop that improves your overall performance.

Summary: How to Optimize Search Ads, Reduce Lost Rank, and Increase Impression Share

These are the primary methods to optimize your Search Ads in Google Ads to decrease Lost Rank and boost your Impression Share. Some tactics, like increasing your budget or changing your bidding strategy, can deliver quick results. Other methods, such as improving your Quality Score, are more indirect and require more effort but lead to more sustainable success.

If you have other effective methods, feel free to share them!

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Originally in Thai. Translated to English with the help of Gemini.