The broadcast world is undergoing a dramatic transformation. While the television screen used to be the main source of video content consumption, viewers are now predominantly watching television content on second screens such as smartphones, PCs, and tablets. Consequently, the emergence of multiscreen television viewing has opened up new monetization opportunities for broadcasters, enabling them to provide personalized and targeted advertising to their viewers.

However, delivering targeted ads on live linear OTT feeds for sports and news can be challenging — especially from scalability, accuracy, and user experience viewpoints. Furthermore, the traditional method of inserting mid-roll ads on the client side often results in users blocking those ads. Broadcasters therefore need an efficient, accurate, and affordable method for delivering real-time targeted advertising.

Drawbacks of client-side ad insertion

Most multiscreen ads today are delivered via client-based ad insertion systems, whereby the ad insertion technology resides inside the device’s media player and ads are played out after being received from an ad exchange network.

There are limitations to client-side ad insertion. With this method, advertisers and broadcasters have little control and visibility on the process. Additionally, ad-blocker software that can be easily installed on client devices enable viewers to skip advertising, which results in reduced revenue for broadcasters, and decreased value for advertisers.

Another issue broadcasters may encounter with client-based ad insertion is video delay. Because ads are sourced from a third-party ad exchange network and delivered to the client side in real time, there can be video buffering, leading to a poor viewer experience.

When advertisements are delivered on the client side, there are separate SDK compatibility requirements between each ad exchange and the end-user device. Without complete SDK integration, viewers aren’t likely to see personalized ads delivered by broadcasters.

Further, as is the case in live sports and news, abrupt ad breaks are intrinsic to the broadcast workflow. With client-side ad insertions, it is simply not possible to create an ad break and return to the live program at a precise break-out point. In addition, the viewer may fall back further in time with each ad that is inserted on the client side.

Server-side ad insertion: Workflow and benefits

Server-side ad insertion has emerged as a viable alternative for creating targeted advertising on multiscreen devices. Under this workflow, the ad insertion process is pushed upstream.

To begin with, at the broadcaster’s premise, content/ads to be replaced are marked using triggers such as SCTE-35, DTMF, Packet 31, or watermarks. The master playlist and content is sent directly as a HLS stream to the CDN and to end users further on.

This HLS stream is also made available to an OTT ad insertion platform that sits between the broadcast source and users’ CDN. The ad triggers are then detected and ad breaks in the stream are tagged as segments of interest. At this point, additional metadata such as the ad-break duration, ad-break type, and splice type are included. The modified playlist is then pushed to the CDN and then to the end users.

As end users view the content, based on user profile, ad requests are sent back to the OTT ad insertion platform. The platform, in turn, sources relevant ads from ad networks, which are connected to various Demand Side Platforms (DSPs). The ads with highest bid rates are determined and stitched into the content stream. In the end, end users can view targeted and personalized ads in a seamless manner.

Compared with client-side ad insertion, the server-side approach offers several unique advantages:

• Control and visibility: One benefit for broadcasters is increased control and visibility on ad insertions. Based on user profiles, relevant ads are fetched from various ad networks. The ads are then stitched together with the program content, resulting in a single stream of content and ads. This leads to a seamless and personalized user experience on the client side, bypassing ad blocker software.
• Support for various ad formats: Server-side ad insertion allows broadcasters to integrate multiple ad formats, including bugs, L-bands, and linear video. The ad viewing experience can be on par with traditional TV.
• Platform agnostic: Using server-side ad insertion, broadcasters can eliminate all dependencies on client-side apps, making the ad personalization truly platform agnostic.
• Ad frequency and reach: As all ads are aggregated from different ad servers by a single server, frequency and reach requirements can now be met more effectively.
• Consolidated reporting: The server-side approach supports a single uniform report for the TV channel/network to advertisers spanning all ad servers.

Server-side ad insertion checklist

When relying on server-side ad insertion, broadcasters need a platform that offers high scalability, the capability to treat news and sports differently, as well as a seamless and reliable trigger method for ad splicing. Let’s take a closer look at how those issues can impact the ad insertion process.

At any time, there may be millions of simultaneous ad requests for the same ad from various types of video players. A large number of concurrent users cause network scaling pressure on the server-side. Broadcasters need to be prepared to support these fluctuations.

Scaling issues can occur on multiple levels, including during the transcoding phase, as each new ad selected for an upcoming ad avail must be transcoded into a broad range of streaming profiles (i.e., bit rates and resolutions). Performing a transcode in real time is highly computationally intensive. Therefore, broadcasters are advised to choose an OTT ad-insertion platform with the compute capability for complex processing, video transcoding, etc.

Personalization also presents challenges related to scalability. Different video and ad combinations need to be stitched together seamlessly, free of glitches if broadcasters want to provide a tailored television experience to viewers. This takes up a lot of network bandwidth.

Another point that broadcasters should consider when switching to a server-side ad insertion platform is live news and sports. Live content needs to be handled more delicately during the ad insertion process, compared with linear and VOD programming. Choosing a platform that offers easy integration with the broadcaster’s existing workflow will ensure the integrity of the live broadcast, eliminating the possibility of ads cutting into the content during network delays or abrupt switches (i.e., quick switch from a live sports game to a timeout ad break).

Currently, there are a variety of trigger types for ad splicing, including DTMF, SCTE-35, Packet 31, and watermarking. Broadcasters will want to thoroughly review each ad insertion trigger methodology, weighing out the pros and cons. Watermarking is highly reliable, offering easy workflow integration and semantically rich playlist support, with no change needed to the ad traffic system. Some platforms will allow broadcasters to utilize a mixture of ad splicing approaches (e.g., watermarks and SCTE-35).

Challenges remain

There is still a lot of work to be done on ad insertion methodologies and approaches for OTT. Industry standards such as IAB VAST, are evolving. Broadcasters need an ad repository across ad networks to procure and transcode the material in advance. While VAST 4.0 proposes universal ad IDs to address this issue, it is an incomplete solution.

While server-side ad insertions on OTT offer several advantages over client-side, it has to resolve some of the broadcasters’ concerns in order to be the de-facto ad insertion solution. For instance, most ad networks continue to rely on client-side tracking for metrics due to a lack of trust in server-side impressions, which could be affected by fraudulent traffic. A few server-side ad insertion providers are working around the problem by introducing thin client-side SDKs to relay accurate metrics.

The other challenges that ad insertion platform providers are solving include custom SDK integration and building standards for in-stream interactive ads. Further, providers need to bridge the gaps in ad tag responses to include information on frequency and reach for a given target profile.

Despite these issues, broadcasters around the world are warming to server-side watermarking technology platforms to deliver personalized and targeted ads on premium live and linear OTT feeds. Without dependency on third-party video delivery apps, broadcasters can now successfully monetize video on every screen. This is all possible, while retaining control, ensuring better visibility on ad insertions, and offering enhanced value to advertisers without compromising on viewer experience.