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What Does it Mean to be LEAN?

By Shailley Singh


If you have been wondering about your LEAN Score and whether your site, app, and creative meet the LEAN principles, worry no more. Today, we are announcing a new roadmap to address critical components of LEAN (Light, Encryption, Allowing Choice, Non-invasive ads). It’s a long story with some twists and turns but I will try to keep it short and straightforward.

In the fall of 2015, we announced the LEAN principles to restore the balance on the open web and provide a safe and pleasant experience for everyone to use the internet for consuming content and services of their choice. Since then, LEAN has served as a set of guiding principles for several standards and industry programs for better advertising across the globe – namely IAB New Ad Portfolio, Better Ads Standards by Coalition for Better Ads (CBA), IAB UK Gold Standard, and more. Most of the tactics underlying the LEAN principles have been well received and adopted widely:

  • Encryption (HTTPS)
  • Allowing Choice (DAA adChoices, Transparency & Consent Framework for GDPR)
  • Non-invasive ads (Coalition for Better Ads)

However…Lightweight ads is one of the areas where we have not observed the required level of adoption and it is one of the most critical principles for better user experience.

An aspirational goal was to develop compliance benchmarks for the LEAN principles and the ability to qualify industry participants as LEAN compliant. To accomplish this goal, two initiatives were proposed – LEAN Scoring and LEAN Seal. Over time it has become clear that the complexity of developing an objective score and enforcing adherence to a seal, along with a lack of industry consensus on either approach, would limit the potential adoption and value of proceeding with these proposals .

In absence of tangible and measurable benchmarks, it has not only been difficult to ascertain compliance with the LEAN principles but it has also been a source of confusion. This has resulted in making it hard to understand the roadmap to LEAN adoption for a company or for the industry. As mentioned, we now have more specific technical standards and guidelines that have been developed based on the LEAN principles and are tangible, measurable, and thus easy to adopt and include in a product roadmap.

In light of limited interest and progress towards formalizing and enforcing the LEAN principles, we will stop work on the LEAN Scoring and LEAN Seal initiatives.

Does that mean the end of the road for LEAN as a program? Yes. But the principles laid out under LEAN remain applicable and are supported by multiple Tech Lab standards and other industry work.

So what is different now? Moving forward, we want to focus on specific standards that  the industry must adopt in order to achieve safe and effective experiences for consumers. This means adoption of the following standards and guidance:


  1. The IAB New Ad Portfolio guidance for lightweight ads incorporates extensive testing to define criteria for ad creatives that allow both ads and pages to load quickly. This means compliance with initial and subload criteria, limiting the number of file requests to 10, and other best practices for developing fast-loading creative. The New Ad Portfolio also provides recommendations on common user interactions inside ads (e.g., expansions, ability to dismiss an ad, video and audio experiences, rich media and animation execution), as well as flexible-sized ad specifications for creatives that adjust to the device size and page design.
  2. DigiTrust ID is for fast-loading content and services. The DigiTrust ID helps reduce the number of network calls thus making page load faster.
  3. Implementing the IAB Europe  Transparency & Consent Framework (TCF) enables the ad-supported ecosystem to process user data in compliance with EU law, and provides consumers with access to and control of their privacy settings. In the US, employing DAA’s adChoices provides consumers with options for online behavioral advertising. Tech Lab is also now looking into how we can help with upcoming privacy laws, so please watch this space for more.
  4. The Coalition for Better Ads (CBA) provides well-researched and proven guidance for non-invasive ads. This requires compliance with the Better Ads Standards for ad experiences and page ad density.
  5. VAST 4.x is for better video delivery and rendering. VAST 4.x (Video Ad Serving Template) includes the use of mezzanine and “ready to serve” media files to deliver the best quality for each device, separation of media file from executable code to eliminate “unsupported” errors and bad code, use of the Ad Request macros to communicate context and get the “best” and most relevant VAST tags.
  6. MRAID 3.0 is for better mobile in-app delivery and rendering. The new MRAID (Mobile Rich Media Ad Interface Definitions) version supports faster and better creative execution by providing guidance for pre-fetched ads, communicating the environment variables, enabling graceful error handling and exits, access to viewability and audibility signals for creative, reduces ambiguity in implementation sequence and standardizes consumer management of ad via close controls
  7. Open Measurement SDK (OMSDK) is to scale and increase mobile in app measurement coverage. Open Measurement SDK reduces Software Development Kit bloat and enables all measurement providers to verify ad viewability and Invalid Traffic with one SDK, standardizing impression and viewability guidance for all ad formats and reducing the risk of presence of unknown code

We recommend all digital advertising programs or charters qualifying better advertising standards to incorporate the above standards directly. These standards are well defined and easy to assess for compliance.

In addition to the above guidance, the Tech Lab team is planning to develop tools and reference implementations to support the education and adoption of the above listed standards. We would appreciate your input (via the to-be-renamed LEAN, DEAL [Detect, Explain Ask, and Lift or Limit], and Experiences Working Group or through other channels) into what would be some of the most valuable food for thought:

We are really excited about this next phase and look forward to your involvement and support!







Shailley Singh, Vice President, Product, IAB Tech Lab