Despite all the technological advances that digital publishing has achieved over the past two decades, slow-loading content remains one of the industry’s biggest scourges.

Nearly 80% of the 1,011 US adults Adobe surveyed in December 2017 said that if a piece of content takes too long to load, they will either stop viewing it altogether or switch to a different device. Survey respondents expressed more sensitivity toward slow loading times than they did to other issues, like broken links or content not displaying properly on a device.

The problem of slow-loading content is particularly acute in digital video. A spring 2017 study from video analytics firm Mux found that 85% of respondents stopped watching video when it took too long to load.

Quickly loading video is simply more difficult than loading text or photos, because video file sizes are much larger. Video ad tags are notorious for containing lots of tracking code. This gives advertisers a better ability to track how users interact with their ads, but it comes at the cost of reducing page speed. There is also high demand for streaming video during peak periods, which is why over-the-top (OTT) video platforms like Netflix get accused of being bandwidth hogs.

Another issue bogging down digital video is that some advertisers don’t adapt how their video loads to better suit particular devices, said Elliot Sedegah, group manager of strategy and product marketing at Adobe. Adaptive streaming products allow content creators and advertisers to create multiple files for the same piece of content, with each file optimized for a certain type of device.

For example, a user on a mobile device with a spotty bandwidth connection will have a slower internet connection than a user on a desktop with stable Wi-Fi. If an advertiser doesn’t use adaptive streaming, both users will get served the same file, resulting in a significant delay in loading time for the mobile user. But if the advertiser uses adaptive streaming, the mobile user will receive a file optimized for that device, which will speed up loading.

“All of these challenges create an environment that causes viewers to abandon the [content],” said Tal Almany, senior director of advanced integrations at video ad server SpotX.

Latency issues are a burden to a booming area of advertising. eMarketer predicts that video ad spending in the US will grow 16.5% to $15.42 billion in 2018.