Case Study

Lazy loading boosts 20minutos viewability up to 73% (+31ppts) and reduces monthly CO2 emissions by 5.2 tons

Google Ad Manager

Henneo is a Spanish media and technology group with diverse publications, digital services, and an audiovisual area. With over 125 years of history, Henneo reaches > 25 million monthly unique users.

The challenge

Henneo sought to optimize ad performance, concentrating on lazy loading for below-the-fold ad slots. Their goal was threefold: to enhance sustainability, increase viewability and improve inventory quality.

The approach

By implementing lazy loading at the ad request level, ads are only requested when there is a high probability of a user viewing them. This achieved faster page loads, reduced latency and improved viewability.

Henneo partnered with Cedara, an external carbon measurement company, to conduct an emissions study and quantify the estimated sustainability impact.

The results

  • +31%
    Viewability2
  • -23%
    Ad Requests2
  • 5.2 tons
    Co2e saved per month2

Savings of 5.2t is the equivalent to¹: 21.300 km driven in a gas powered vehicle or 420,403 smartphones charged

Implementing a lazy-load solution directly from the ad request not only demonstrates our commitment to sustainability but also enhances the user experience. This change has been crucial in reducing our carbon footprint, and we have achieved it without compromising our viewability, CPM, or performance metrics.

Aitana Nunez, Manager, Henneo

  1. Calculated using EPA Greenhouse Gas Equivalencies Calculator: https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator

  2. Publisher results 2025. Individual results may vary.

You might also like: