Research: How Start-up Delays, Interruptions and Rebuffering Effect Video Viewing Abandonment Rate

A research paper by S. Shunmuga Krishnan, Akamai Technologies, and Ramesh K. Sitaraman (pictured) University of Massachusetts, Amherst & Akamai Technologies, examines the impact of viewing Quality of Experience on the viewer willingness to continue watching the video.

One of the surprising findings [see chart below] is that mobile users are much more patient compared to users accessing video through fixed connections (fiber, DSL or cable), although viewers tend to abandon shorter videos (expected to be more common in mobile) at a higher rate. 

ABSTRACT

The distribution of videos over the Internet is drastically transforming how media is consumed and monetized. Content providers, such as media outlets and video subscription services, would like to ensure that their videos do not fail, startup quickly, and play without interruptions. In return for their investment in video stream quality, content providers expect less viewer abandonment, more viewer engagement, and a greater fraction of repeat viewers, resulting in greater revenues. The key question for a content provider or a CDN is whether and to what extent changes in video quality can cause changes in viewer behavior. Our work is the first to establish a causal relationship between video quality and viewer behavior, taking a step beyond purely correlational studies. To establish causality, we use Quasi-Experimental Designs, a novel technique adapted from the medical and social sciences.

We study the impact of video stream quality on viewer behavior in a scientific data-driven manner by using extensive traces from Akamai’s streaming network that include 23 million views from 6.7 million unique viewers. We show that viewers start to abandon a video if it takes more than 2 seconds to start up, with each incremental delay of 1 second resulting in a 5.8% increase in the abandonment rate. Further, we show that a moderate amount of interruptions can decrease the average play time of a viewer by a significant  amount. A viewer who experiences a rebuffer delay equal to 1% of the video duration plays 5% less of the video in comparison to a similar viewer who experienced no rebuffering. Finally, we show that a viewer who experienced failure is 2.32% less likely to revisit the same site within a week than a similar viewer who did not experience a failure.

See "Video Stream Quality Impacts Viewer Behavior: Inferring Causality Using Quasi-Experimental Designs" - here.