November 13, 2017

What the IAB’s New Ad Portfolio FLEX/LEAN Guidelines Mean for You



Mike McNulty

Product Marketing Manager

While the benefits of HTML5 far outnumber its limitations, some key areas still lacked proper standardization and adoption, resulting in executions with poor user experience, inflated file sizes, and a lack of scalability on an industry level.


Basically, with HTML5, we began migrating all of Flash’s baggage and decades-old practices over to this new era of the web. The new IAB Ad Portfolio puts forth new FLEX/LEAN specs that identify many of the shortcomings that have come about, and identify these gaps and begin rectifying them.

While some see the change as an attempt to dilute digital advertising, Sizmek views these guidelines as an opportunity to reimagine solutions that offer better performance, a more thoughtful user experience, and flexibility throughout the advertising ecosystem. Sizmek wants to create impressions that inspire, so consumers engage willingly with content, without annoyance, while ensuring uniformity across the many devices users interact with daily.

LEAN Guidelines

Let’s take a look at the LEAN specs, which center around improving user experience. The LEAN guidelines intend to solve the problem of intrusive and annoying ad delivery and functionality, and thus address the problem of the increasing number of users who install ad blocker technology. The LEAN guidelines institute specifications that control ad load. They no longer recognize formats such as interstitials and popups that add to initial load time and prevent users from viewing the intended content. In addition, functionality like rollovers and timed ads are also being deprecated. Implementing the LEAN guidelines will ultimately mean a lightweight user experience. This will result in quicker page load times and ensure a less disruptive experience, so users are in control of the content they wish to interact with.

FLEX Guidelines

The Flexible side of the standards are geared toward:

  • Addressing the many different devices on which users consume and engage with content
  • Aligning publisher sites to convey creative across this multitude of different devices without loss of quality

The FLEX specs aim to move away from typical, static dimensions and progress to an aspect ratio-based size that will be able to scale, while holding its resolution regardless of the user’s device or publisher’s site. With this, creative becomes nimbler by being able to serve one ad to a broader range of sizes responsively. Publisher sites can get more out of their inventory by implementing these aspect ratio ad units to encompass a range of sizes that can be used, instead of just one size at fixed dimensions.

What’s Next: Big Decisions

The IAB has always issued specifications as general recommendations but ultimately left their execution up to the discretion of the publisher. The FLEX/LEAN specs are no exception. While it would be foolish to think the IAB would release a New Ad Portfolio without the market’s general approval, let’s consider what this means holistically. The LEAN guidelines share in a common practice most publishers, sites, point solutions, and so on currently follow, so the technical change is minimal, if at all, for most. The deprecation of the formats and functionality will force advertisers, publishers, and media agencies to come to a decision: Do they continue to run one of the most widely used, versatile, and highly viewable formats (that happens to be one of the most intrusive formats), the interstitial? Or do they align with both the IAB and Better Ads Coalition to migrate to a more user-friendly alternative and make a conscious decision to put the user first?

It should be noted that the FLEX standard is a bit more of a modification to the infrastructure of the entity’s site or system. While these changes may need some intuitive thinking to happen behind the scenes, the payoff will come from the scalability on any given site or placement.

It is already Q4, so will sites actually restructure sites in time for the impending deadline of January 1, 2018? Adoption will most likely increase through the middle and latter part of H1 2018, and continue through H2. The adoption of the IAB’s FLEX standard ensures proper responsiveness for brands and advertisers, and streamlines the flexibility throughout the ecosystem, resulting in less development and more opportunity across their site(s).

Sizmek’s Approach to FLEX/LEAN

Sizmek is currently in the process of finalizing our approach to comply with these new guidelines. We are working with our publisher partners, figuring out the most efficient path forward. It is through these key partnerships that Sizmek continues to help clients and advertisers navigate change. As always, Sizmek is in full support of IAB standards and guidelines, and we intend to continue this support as we usher in a new and exciting time in digital advertising.

About the IAB 
The Interactive Advertising Bureau (IAB) empowers the media and marketing industries to thrive in the digital economy. Its membership is comprised of more than 650 leading media and technology companies that are responsible for selling, delivering, and optimizing digital advertising or marketing campaigns. The trade group fields critical research on interactive advertising, while also educating brands, agencies, and the wider business community on the importance of digital marketing. In affiliation with the IAB Tech Lab, it develops technical standards and best practices. IAB and the IAB Education Foundation are committed to professional development and elevating the knowledge, skills, expertise, and diversity of the workforce across the industry. Through the work of its public policy office in Washington, D.C., IAB advocates for its members and promotes the value of the interactive advertising industry to legislators and policymakers. Founded in 1996, the IAB is headquartered in New York City and has a San Francisco office.