The news: Uber partnered with ad measurement firms Kantar and Adelaide to launch a custom attention metric for in-ride ads and Uber Eats checkout screens, the companies announced Tuesday.

The partnership is Adelaide’s first custom, platform-specific attention metric partnership. “We’ve done a couple of one-offs with publishers … but nothing of this scale before,” Adelaide CEO Marc Guldimann told AdExchanger.

The attention metric is only available to “premium” Uber ad partners. The company plans to extend it to more advertisers in the future.

The attention economy: Attention has become an important measurement for advertisers, replacing metrics like viewability—which served as a decadelong standard for ad performance but only measured how visible an ad was at a moment in time.

Despite the pivot, what qualifies as “attention” can vary significantly between platforms, making it difficult to measure success for cross-platform campaigns. Uber pushes the industry another step in the direction of platform-specific attention measurement, but industry groups are working to establish universal standards.

Uber’s angle: Uber’s ad business reached a $1.5 billion annual run rate in May, up 60% YoY—making it one of the fastest-growing sectors of Uber’s business. The nature of the app, which has users tracking deliveries or their own transportation, means Uber has a unique captive audience that makes attention metrics all the more valuable.

Uber’s turn to attention measurement is a sign that viewability is becoming outdated as platforms and advertisers look for deeper insights into how ads drive brand lift, action, and recall—not just if an ad was visible or not. The ridesharing service’s Q3 results contained “one of the largest trip volume increases in the company’s history,” which means more consumers for advertisers to attempt to reach.

What this means for marketers: As the ad industry inches toward universal standards, Uber’s platform-specific attention metric shows the challenges in creating a one-size-fits-all approach.

The push toward standardization is taking flexibility into account—the IAB and MRC have said they are aiming to establish methodologies for individual signals like eye-tracking or surveys but won’t limit signals can be used, which will allow platforms to develop proprietary offerings—but advertisers will likely have to navigate an ecosystem with many platform-specific metrics.

Uber’s strong quarter also shows that, despite consumer concerns about the US economy, ridesharing is still in high demand. As ridesharing services debut new advertising formats and metrics, strong consumer demand will drive advertisers to the sector.