Choosing Between Progressive Download and Video Streaming

By Peter Coppola, Vice President, Product Management
Limelight Networks

Video providers have many choices for delivering content online, but one of the first decisions faced is whether to make video downloadable or available through an online streaming media player.

In the past, video downloads delayed the consumer viewing experience by forcing viewers to wait until the entire video file had been saved locally, but that concern has faded with the adoption of advanced progressive downloading. Simply implemented using HTTP and TCP/IP on conventional web servers, progressive downloads can be viewed virtually instantaneously. By contrast, streaming video is technically more complex, though it provides advantages in scale, quality, and security—and allows viewers to navigate to any point within a video file.

In the simplest model, users may not care which technology is used for content delivery, as long as the video they want is accessible. The decision for providers, however, requires examination of several factors. A few of the considerations for online video providers include:

• Nature of the content: Is your content short or long? Is it a small web video or full-screen H.264? How big is the library, and what are the assumptions for protecting copyrights?

• Expected user interactions: How fluidly will the user navigate through the content? What will the user experience be over a variety of connection scenarios?

• Publisher business model: Are you relying on advertising and user-generated content? Or are you charging directly for the content?

• Content security: The publisher may have both an interest in and an obligation to protect the content from piracy. If you are considering delivering high-value content rather than user-generated content, this will be a significant consideration.

• Economics: From a purely technical perspective, the progressive download model can be attractive since it is low-cost and leverages generic technical expertise. However, it is worth noting some of the hidden costs. Progressive download is less efficient from the perspective of network utilization: If the user consistently abandons the video one or two minutes in, you have essentially paid for the delivery of content that was not consumed.

For most online video that is not user-generated, streaming is the most practical option for delivery. Movies are an exception because there is value in owning some movie selections over merely accessing them when a connection is present. By and large, however, viewers are content to consume video without owning it, and where that’s the case, the quality and security advantages of video streaming outweigh other costs.