OTT Monetization: Analyzing the benefits of client-side ad insertion and server-side ad insertion hero graphic

OTT Monetization: Analyzing the benefits of client-side ad insertion and server-side ad insertion

Posted On

By Elisabeth Kindig

Benefits to OTT and mobile advertising include targeting specific audiences based on demographic and behavioral traits as well as using dynamic ad insertion to personalize the ads. Data collected from viewing habits is collected and analyzed to better inform which advertisement should be displayed. There are additional advantages to advertisements informed through cross-device data, which is collected when OTT devices are linked to mobile devices, tablets, smart TVs, and other devices.

This article discusses how dynamic ad insertion solves OTT service providers’ two biggest concerns: it improves the user experience and increases revenue. Dynamic ad insertion is discussed in detail including client-side ad insertion and server-side ad insertion, and why a combination of both is the best approach for today’s audiences. This article also discusses Hybrid DAI architectures, which combine modern CSAI with SSAI, to handle demand at scale while offering price efficiency.

Analyzing the Benefits of CSAI and SSAI

Advantages of CSAI:

Client-Side Ad Insertion has been the ongoing standard for inserting video ads into a video stream. CSAI has some key benefits which are important to discuss. For instance, CSAI has superior metrics because the advertiser can monitor the metrics directly through the SDK. Most current ad technologies, such as viewability, interactivity, and click-throughs, are built on the client-side. Another significant advantage to CSAI is the ability to serve VPAID Ads.

Disadvantages of CSAI:

As video ecosystems continue to evolve, issues have arisen when relying on the video player or the device to combine the ad with the content. For instance, there can be an excessive amount of latency and buffering if the ad-serving system is slow or the device has poor broadband access. CSAI is particularly unforgiving with live broadcasts, such as sports or news programming.

Ad-blockers can easily detect CSAI while malware can corrupt ad calls and insert competing advertisements. In addition, multi-platform support is challenging for client-side apps, and the apps are dependent on ad ecosystem components because they are client-side, which makes them hard to switch out.

CSAI Architecture:

Early attempts at online video advertising had the commercial spot “burnt in” to the video asset. This so-called static advertising did not take demographics into consideration and was always attached to specific content long after an on-air campaign has ended. Due to drawbacks of “burn in” commercials into video assets, online services moved to a client-side model which inserted specific, relevant advertising into the video stream at the point of playback. This ensured that the commercials were appropriately targeted and timely, because the commercial could be changed for each viewing.

This approach offers two main benefits. The first is that the CPM (cost per thousand impressions) is higher than with static advertisements because the demographics are better identified. But that is not all: end users find a personalized advertisement less intrusive because it offers something more in line with their interests. A luxury car fan will be much more interested in an ad from BMW or Mercedes-Benz than a generic soda or grocery store spot.

The established standard for this is VAST (video ad serving template), published by the Interactive Advertising Bureau (IAB). The fundamental architecture of client-side advertising provision is shown in Figure 1.

Figure 1

Advantages to SSAI:

Server-side ad insertion, also known as “ad stitching,” is a superior choice for live programming, simulcast and linear programming. The user experience with SSAI is improved by having one continuous stream of content when alternating between content and ads. Latency is also reduced. There is also a greater chance of the advertisement reaching the viewer with SSAI as advertisements are inserted in the video stream at the point of delivery, and this opens up real-time bidding through programmatic technology.

Disadvantages to SSAI:

SSAI may not be very advantageous for a small publisher who has limited video inventory. SSAI alone does not support Clickable/Interactive/VPAID Ads. It needs support from SDKs to build such features. VAST 4.1 standard overcomes most of the challenges. For example, it has segregated out Linear Video parts and Interactive parts of an ad. In VAST 4.1, IAB has officially depreciated VPAID format. Text ad Industry will take some time to accept these changes, until then VPAID ads will continue to be part of the ad industry.

SSAI Architecture:

Server-side advertising insertion (SSAI) is reminiscent of traditional TV advertising because both content and commercials arrive in a single stream from a single source. The difference with SSAI is that the advertising is no longer static, and is dynamically inserted prior to delivery to a video player.

SSAI requires an architecture that supports just-in-time packaging of content. Rather than content being pre-packaged for each delivery format, just-in-time packaging takes the native content from both the program store and the advertising servers, and adapts it on the fly at the point of request.

In this architecture (see Figure 2), the manifest remains with the service provider. When a consumer requests a particular video stream, the program is requested from the server. It arrives complete with markers for commercial insertion, usually in the form of SCTE 35 (for compressed video) or SCTE 104 (for SDI video) standard cues.

Figure 2

In contrast to CSAI in which the receiving device makes calls to the advertising servers and provides the response for the impression count, in the SSAI model, the video delivery platform makes VAST calls with end-user metrics to the advertising servers and receives the appropriate commercials. These are cut into the video upstream of encoding or transcoding.

This architecture allows for the dynamic insertion of advertising into live streams, and even into sports broadcasts when it is not known in advance how long a program break will be. By using the same SCTE 104 or SCTE 35 cues that broadcast playout systems use, a server-side advertising insertion platform can perfectly fill the break on the fly.

Hybrid Solution: Best of Both CSAI and SSAI

In order to maximize returns on advertising, a hybrid solution that combines the best of SSAI with the best of CSAI is ideal. SSAI brings in smooth TV-like experience across a multitude of devices and platforms. CSAI requires more developmental efforts of building and integrating SDKs, yet it gives very accurate ad tracking metrics and covers more ad formats.

The result of combining CSAI with SSAI in a hybrid solution, such as ExpressPlay’s Dynamic Ad Insertion, is a price effective ad personalization and monetization solution across devices and platforms that does not compromise on user experience and also reduces developmental/integrational efforts that does not compromise user experience and reduces development time.

Using the hybrid solution, SSAI can be used for streaming platforms such as FireTV, AppleTV, Roku, Chromecast, etc, where CSAI solution is very difficult to implement. SSAI and CSAI can be used in conjunction with mobile devices, tablets, laptops and desktops to get both a TV -like experience and accurate ad metrics.

The Intertrust ExpressPlay Ads ™ suite represents a single service that provides content distributors, network operators, and broadcasters all of their media monetization requirements in a highly cost-effective and efficient way.

media CTA Banner

Related blog posts


Common attack modes used in the piracy ecosystem

Read more


What’s behind the surge in online video piracy?

Read more


How to Trust Your Player: Building an OTT Service for Today’s World

Read more