How to Increase Traffic 2.5x from Google Images ━ ON Clinic use case

Effective image optimization can help drive traffic to your website, but it doesn’t guarantee that every image will be indexed. It’s essential not only to ensure your images meet search engine requirements, but also to confirm they are indexed and generating clicks from Google Images.

In this case study, the team at digital marketing agency adStorm Marketing shares how they addressed image indexing challenges and boosted organic traffic from Images search.

About the Partner

The ON Clinic network launched its operations in Ukraine in 2007. Today, it unites more than 20 medical centers across 11 cities in the country and operates in Poland and Slovakia under the Doctorpro brand. The brand continues to grow, expanding its geographic reach and strengthening its expertise.

ON Clinic stands for precise diagnostics, effective treatment, exceptional service, and a strong in-house digital marketing team. Leveraging its extensive experience in the medical sector, the company founded the digital marketing agency adStorm Marketing to help other healthcare businesses grow and thrive in Ukraine.

Task

For commercial pages dedicated to clinic departments and medical services, as well as for blog articles, we create unique, custom-designed images with the help of a designer. These images serve as valuable content, making complex information easier to understand.

All images are optimized in accordance with Google’s recommendations for search ranking.

Optimization includes:

• images implemented using the src attribute of the <img> element;

• WebP format applied to reduce file size without quality loss;

• responsive images set up via the srcset attribute of the <img> element;

• multiple versions of each image provided for different screen sizes;

• alt attributes written with relevant search queries in mind;

• browser-based lazy loading enabled for images.

Overall traffic from Google Search is growing, but the increase from Google Images remains significantly lower.

Data from Google Search Console with the search type set to “Image” for the period April 2024 – June 2024.

Analysis of Google Search Console data showed that image content was accessible to the Googlebot but not indexed.

Data from Google Search Console

Example of missing image indexing according to Google Search Console data

We set ourselves the goal of finding a solution that would ensure all images in the content are indexed and drive increased traffic from Google Image Search.

Solution

To improve image indexing, we implemented two technical measures:

1. Added images to existing structured data types — Product and Article;

2. Included images in existing Sitemap.xml files with the image extension.

We then compared the structured data before and after adding the images.

Example of article before changes: with a single image used as the article cover

Example of Article-type structured data after adding images

When adding images to the Sitemap.xml files, we followed Google’s recommendations.

Example of Sitemap.xml file with images

In June 2024, visual content was added to the structured data, and in August — to the Sitemap.xml file.

After these changes, the images began to be indexed, and the number of clicks from Google Images search started to grow significantly.

We repeated the test on another project with a similar situation. This time, the actions were reversed with a time gap to determine the impact of each step. First, we added images to the Sitemap.xml file, and later expanded the structured data.

Adding images to the markup proved to be more effective than updating the Sitemap.

Result

Trends in clicks and impressions from Google Images in the Looker Studio report for the period 2023–2025. 

Data from Google Search Console is transferred to BigQuery and visualized in Looker Studio. This setup allows us to track click and impression history for a period of over 16 months. Data storage in BigQuery began in July 2023.

Image traffic from September to December increased 2.5 times, reaching 61,000 clicks — compared to 24,000 clicks during the same months last year.

The average position in Google Images improved from 27 to 13.

Conclusions

1. Unique visual content with proper SEO optimization is essential, but without providing search engines with image information in structured data, those images may remain invisible to Google.

2. The key driver of traffic growth from Google Images was adding images in the content to structured data. Once all visual elements were specified in the Article and Product markup, the search engine indexed the images.

3. Including images in the Sitemap.xml also produced positive results, but its impact on overall traffic growth was less significant.

4. A repeated test on a similar project confirmed that marking up images in structured data delivers consistent results. Even with delayed implementation — three months later — traffic growth from Google Images search was observed again.

The views expressed in the guest case may not reflect the opinions of the editorial team or Netpeak specialists.