If a mobile ad is displayed, but not viewed by a human or simply not rendered properly, does the advertiser pay? The answer is yes, but two top advertising trade groups are working to establish a standard that will address this wastage and ad fraud through a uniform means of tracking whether ads can be seen in mobile apps.

Viewability is a huge headache on mobile – where the variety of ad formats and the way consumers interact with them (scrolling in a newsfeed, not clicking individual banners, for example) makes it a difficult one to call. To complicate matters, both Flash and cookies – URL referrers and trackers that are ubiquitous across all major desktop browsers – are completely absent from mobile.

Moreover, the mobile ad ecosystem of buyers and sellers is, in itself, a bottleneck. While ad buyers insist on purchasing only mobile ads that people can actually see, many publishers are less eager to lift the lid on this data. Their reluctance can be linked to that fact that impressions (CPMs) not click-throughs (CTRs) are the measurement that defines their business and their bottom line.

Currently, tracking ad viewability on mobile apps is a complicated process as app developers and publishers must integrate software from multiple third party providers. It’s a process that costs resources and – more importantly – can slow down the app. This is critical as a recent HP- sponsored study by Dimensional Research shows that most consumers quickly lose patience, and will even delete, apps that take longer than 2 seconds to load and perform its actions. The result is a trade-off between viewability (for the advertiser) and usability (for the consumer).

To strike a needed balance the American Association of Advertising Agencies (the 4A’s) and the Interactive Advertising Bureau (IAB) have thrown their support behind an open source initiative aimed at standardizing viewability measurement for mobile apps. The goal is to jointly develop a single code base that mobile publishers can plug into their apps, letting advertisers pull data on viewability in a standard fashion, Joe Barone, managing partner of digital ad operations for GroupM and chairman of the 4A’s Digital Operations & Technology Committee, told the WSJ.

The organizations will oversee efforts to develop a standard tracking code, with the input of various constituencies from across the ecosystem. “This will be a very regimented, very democratic process,” Alanna Gombert, general manager of the IAB Tech Lab, told the WSJ.

The initiative comes at a time when concerns about ad viewability and accountability in the industry are high, magnified by a string of serious miscalculations by Facebook. The mobile ad giant has publicly admitted to overstating or understating the metrics that publishers and advertisers use to measure ad effectiveness on the platform and the value of Facebook ads.

It’s important to have Facebook and Google, which account for 85 cents of every new ad dollar spent on digital, on board, but it remains to be seen if thy will adopt and implement third-party tracking code of any kind.

While there is growing need for a consensus on viewability tracking, and a single code to enable it, change may come slower than we think. Many ad buyers and publishers prefer to work with their preferred vendors to track and calculate ad effectiveness. Moreover, the vendors behind these technology solutions worry an open source approach would effectively replace their proprietary tracking code and potentially devalue their companies.