In a trend championing custom display units, American broadcaster NBC News has launched two new types of ad units designed specifically with viewability in mind.

Developed in-house, custom display MACH and ‘ping pong’ unit BETTER, which scrolls through images as the user moves down the page, have been created to meet advertisers’ demands for viewability. Both ad units remain in readers’ view for longer than the one second required by the IAB standards and they resize themselves for any device.

The move aims to better engage NBC News’ users by encouraging them to stay on the site longer and offering more information. Some of the features introduced in the move will include a front page allowing readers to see a full story without the need to click through and video players where users can watch an unlimited number of videos with a single pre-roll ad.

Talking to Digiday, NBC News’ vp of digital product Moritz Gimbel highlighted advertising is part of user experience and the new ad units were thought of at “inception rather than as an afterthought”. The new designs focus on ratio and not pixels, which means ads occupy a portion of the screen rather than a fixed spot on a page.

NBC News’ svp of digital, Nick Ascheim, believes by aiming to make ads more distinct – and therefore more valuable to advertisers –  the company helps marketers find new ways to tell their stories.

“And because the new design provides such a visually rich environment, we expect to see higher engagement with both the ads and the content, which is a win for us and for our advertising partners,” he explained.

NBC News is planning to roll out another new vertical, Think, in a few weeks.