How to minimise the impact of advertising on the Core Web Vitals CLS score?

Last year, Google announced a new Web performance indicator: Core Web Vitals measure the load time (LCP), interactivity (FID) and visual stability of a site (CLS). This initiative aims to increase publishers’ awareness of the user experience and thus optimise the ranking of their sites in the SERPs. These new metrics, which will come into effect in June 2021, are in addition to existing SEO indicators such as mobile usability, secure browsing, HTTPS security and guidelines for intrusive pop ups.

The Google Page Experience criteria © Google

With these new essential criteria, all the elements that make up web pages are analysed by the leading search engine’s algorithm and can have an impact on its overall performance: text, video, images, code and… advertising. How to minimise the impact of advertising on Core Web Vitals and protect your SEO? Before sharing our solution to optimise your CLS score, let’s start by understanding what Core Web Vitals are. 

Should we fear Core Web Vitals?

Google’s objective is clear. With the Core Web Vitals, the Mountain View giant wants to favour sites offering the best user experience – and, conversely, to penalise non-optimised pages with slow loading times, that aren’t mobile friendly, or have overly intrusive advertisements or a content shift that alters user navigation.

Publishers did not take the announcement of the Core Web Vitals lightly as last November Google reported “an average 70% increase in users interacting with Lighthouse and PageSpeed Insights”, two tools that measure UX quality. 

The 3 CWV indicators

  • LCP (Largest Contentful Paint): This metric analyses a site’s loading time. A good LCP should occur within 2.5 seconds once a page has started to load.
  • FID (First Input Delay): This factor measures the time it takes for a page to become interactive. The FID should not exceed 100 ms. 
  • CLS (Cumulative Layout Shift): This indicator considers the visual stability of a page. For a good user experience, the ideal measurement is less than 0.1.

We focus our efforts on this last metric, CLS, to avoid content skipping caused by the subsequent loading of ads. Publishers have everything to gain by optimising the Core Web Vitals. Maintaining a good UX is an essential key to increasing traffic. By optimising their CLS score, we also support publishers in their audience acquisition.

How do we optimise the CLS score at Opti Digital?

At Opti Digital, our solutions include the implementation of multi-sizing and dynamic refresh within ad slots, which can cause unexpected content jumps. To avoid this, we have developed a new solution to optimise publishers’ CLS score directly from our tags. We create a minimum height parent div to the ad tag divs. If the creation of a smaller size wins the market, we also set a vertical center in CSS. This helps to visually reduce the margins that can appear when centering the ad height.

For example, here are the minimum set sizes we implement:

  • 250px for Keypad placements on Mobile
  • 280px for in-read Keypad placements on Desktop computers
  • 600px for Large Angles
  • 250px for Mega Banner sites

Read: The best advertising formats in 2021

Thanks to this solution, one of our editorial content clients has reduced the number of content jumps on their site, providing a better user experience for their audience:

CLS score of our client before and after Opti Digital’s optimisations (in January 2021 & May 2021)

In addition, since the implementation of ad tag optimisation, a classified ad site publisher that generates leads in the real estate and automotive sectors has observed an improvement in its conversion rate.

With our Core Web Vitals solutions, publishers can continue to monetise their ad inventory without disrupting the user experience, ensuring a good position in the SERPs for audience acquisition.

Want to test our solutions? Do you have any questions about the optimisations we implement to improve your CLS score? Please contact your Account Manager or write to us here.

Optimise your cross-consent monetisation and visualise the results with our centralised Business Intelligence

Business Intelligence Cross-Consent Opti Digital

With the consent of the user, without, or no choice given… How do you monetise advertising inventories in these cases? Opti Digital responds to this problem by offering optimised monetisation according to consent and respectful of the GDPR. To facilitate management in these different environments, Opti Digital innovates and launches the first Business Intelligence tool which gives the media a centralised vision of their cross-consent advertising monetisation. Explanation:

Publishers forced to use several Ad Servers according to consent 

In France, the media have been forced to comply with the new CNIL guidelines (Commission Nationale de l ‘Informatique et des Libertés), which entered into force on April 1. In Europe, it is the ePrivacy 2021 draft regulation which raises the question of alternatives to traditional cookies. The GDPR (General Data Protection Regulation) already requires a website to get the explicit consent of its users before employing trackers to process their personal data.

The purpose of these guidelines? To put the Internet user more at the centre of concerns and give them back control over the privacy of their data.

However, most publishers use Google Ad Manager’s Ad Server to oversee their inventories, a solution that only works with cookie consent. Much of the media choose to adopt an alternative diffusion tool to generate advertising revenue depending on the case. Our publishers combine several Ad Serving tools to manage their monetisation, including Google Limited Ads, complemented by our new Opti Digital Ad Serving solution.

The non-consent alternative offered by Opti Digital

To support publishers in the face of European regulations, we have anticipated their need to monetise inventories in all potential cases, with or without consent and no choice given. We have developed an alternative monetisation solution that is GDPR compliant: Opti Digital Ad Server aka ODAS. This technology makes it possible to run advertising campaigns without using personal data from the Internet user.

In the absence of a choice, the publisher can rely on their legitimate interest. As a first step, we call on Google’s Limited Ads to simplify the delivery of direct campaigns and compatible (cookieless) programmatic partners for our publishers. Then, we complete the monetisation via ODAS to diffuse self-promotion campaigns, programmatic advertising, direct or performance-based campaigns selected by the publisher or by Opti Digital.

If the Internet user objects to the processing of their personal data, we directly activate our Opti Digital Ad Server monetisation solution. Consent recovery campaigns make it possible to switch the Internet user’s choice back to positive consent in order to optimise advertising profitability. With the publishers we support, we collect hundreds of consents every day.

Over 100 media outlets have chosen our innovation for their cross-consent advertising including,,,…

Reconciliation of Ad Server data

Since the creation of Opti Digital in 2018, we have been building our analytic tool to meet the needs of publishers. To enable them to have a centralised view of their advertising revenue, we have developed the first cross-consent Business Intelligence tool.

All the Ad Server data used, with or without consent, is grouped together in our analytics table to guide publishers in their strategic decisions and drive their media growth. Thanks to our expertise in Data Visualisation, we allow them to interpret the performance of their campaigns by offering them a detailed analysis of their advertising earnings.

Our latest updates include, in particular, cross-consent analysis to provide insight into revenue in all 3 circumstances: with consent, without consent, and no choice given with legitimate interest. The major new features of our reporting tool include an analysis of inventory volumes, revenue, eCPMs and page RPMs (revenue per 1,000-page views) according to the consent received and the Ad Server used.

Cross-consent analysis of a French website

Thanks to our management tool, we improve publishers’ revenues every day in all situations: with or without consent. And you, what monetisation strategy have you chosen for your website? Contact us to discuss it further.