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  • Writer's pictureSebastian Strootmann

SSAI & DAI: Your Essential Guide to Server-Side Ad Insertion

Updated: Jun 22

couple watching tv content with ssai on a wide modern tv screen

Server-Side Ad Insertion (SSAI), also called Dynamic Ad Insertion (DAI), is a technology that stitches targeted ads seamlessly into a single video stream increasing viewer satisfaction with a superior user experience, while boosting both platform operators’ revenue and advertisers’ conversions.

According to Statista, AVOD market worldwide is expected to have a steady compound annual growth rate (CAGR) of 9.53% from 2024 to 2027, resulting in a projected market volume of $ 63.50 bn by 2027.

This means that relying on efficient ad delivery methods like Server-Side Ad Insertion (or Dynamic Ad Insertion) will prove to be key for OTT TV publishers’ success.

Discover all you need to know about SSAI and DAI in this guide and get inspired by substantiated opinions from global experts who have been working in the MediaTech industry for years.

Table of Content

What is Server-Side Ad Insertion (SSAI)? What is Dynamic Ad Insertion (DAI)?

different people reached by dynamic ads with targeted products

Server-Side Ad Insertion (SSAI) and Dynamic Ad Insertion (DAI) are two sides of the same coin, or in this case the same technology.

Server-Side Ad Insertion (SSAI) is the technical concept used in online video streaming that describes advertising being inserted into the content at the server level in the cloud rather than at the player level (the client-side).

This means ads are stitched into the video stream before it reaches the viewer's device, typically utilizing a Content Delivery Network (CDN) in combination with an Ad Server, and an SSAI platform like The method allows for a seamless viewing experience without the very common buffering issue or delays caused by ad loading in online streaming environments.

Dynamic Ad Insertion (DAI), on the other hand,  is the business concept referring to the fact that ads are dynamically inserted into the content stream in real-time based on various targeting criteria. Unlike traditional TV broadcasting where ads are usually predefined and served to all viewers identically, DAI allows for the personalized delivery of ads to individual viewers or households.

This targeted ad insertion process can potentially take place both at client-side or server-side level but — nowadays — Dynamic Ad Insertion (DAI) is usually used as a synonym of Server-Side Ad Insertion (SSAI).

To implement SSAI / DAI properly, ad slots within the content need to be marked either with SCTE-35 ad markers (live linear) or cue points (VOD). This way, when a viewer requests a video, the ad insertion system — in collaboration with Ad Servers and Supply-Side Platforms or SSPs — dynamically selects and inserts the most relevant ad into the reserved slot based on factors such as viewer demographics, interests, location, and behavior.

This ensures viewers receive ads that are tailored to their preferences, leading to higher engagement and conversion rates that positively affects both advertisers and TV publishers who can now ask for premium fees for micro targeted advertising placements.

How does SSAI differ from Client-Side Ad Insertion (CSAI)?

picture showing the differences between csai and ssai

Server-Side Ad Insertion is a newer and more optimized ad delivery method compared to the traditional Client-Side Ad Insertion approach. As said, SSAI involves stitching ads into the video stream at the server level before reaching the viewer's device, ensuring seamless playback without interruptions. In contrast, CSAI inserts ads on the client side, relying on the capabilities of the viewer's device and player. Therefore, this technology is more susceptible to buffering or delays caused by ad loading and communication with the ad server. In addition, CSAI delivers ads in their original format, which may not be optimized for the viewer's device or connection speed, while with SSAI the ads are transcoded and optimized for the specific device and bandwidth of the viewer. 

Server-Side Ad Insertion makes it also more difficult for ad-blockers installed on the client machine to block ads. This is because the ads are delivered as part of the video stream, and not as separate requests. In contrast, Client-Side Ad Insertion requires a separate request to be made for each ad, which can be easily detached by ad-blocking software.

Overall, SSAI provides a significantly enhanced ad experience compared to CSAI due to its ability to reduce ad latency, prevent ad blocking, and provide higher-quality ads and more accurate analytics resulting in a greater monetization potential for TV operators.

Can SSAI be used for live streaming as well as Video-On-Demand content (VOD)?

group of friends watching a football match on tv with server-side ad insertion

Server-Side Ad Insertion (SSAI) can be used both for live streaming and on-demand content (VOD), offering versatile monetization capabilities for media operators and publishers. 

In the context of live streaming, SSAI enables real-time ad insertion into live feeds, ensuring seamless integration of ads without interrupting the viewing experience. This is crucial for events such as sports matches, news broadcasts, concerts, and gaming streams, where advertisers can target a large, engaged audience. 

Similarly, for on-demand content like movies, TV shows, and archived videos, SSAI allows for Dynamic Ad Insertion based on viewer demographics, interests, and behaviors. By stitching ads server-side into the video stream, SSAI ensures optimized ad targeting, better ad completion rates, and improved monetization potential also for VOD platforms. 

Overall, SSAI provides a unified solution for delivering targeted advertisements across live streaming and video-on-demand, enabling TV publishers to maximize ad revenue and enhance viewer engagement for synchronous and asynchronous video content.

pavlin rahnev
"For their large-scale sports events, our customers rely on us partnering with scalable ad insertion solutions such as Their cloud based architecture allows us to scale to peak concurrency while also staying economical in VOD environment or during periods of lower viewer numbers." - Pavlin Rahnev, CEO at PlayboxNeo (playout provider)

How does Server-Side Ad Insertion work?

graphic showcasing server-side ad insertion workflow

Server-Side Ad Insertion (SSAI) involves a series of technical processes that seamlessly integrate advertisements into the content stream before delivering it to viewers. Here's how SSAI typically works from a technical perspective:

  • Content Preparation: The video content, which may be live or on-demand, is prepared for streaming. This content is typically hosted on a video server, origin or Content Delivery Network (CDN) and is accessible via URLs or manifest files (e.g., HLS, MPEG-DASH).

  • Ad Decision and Selection: When a viewer requests the video content, the video player or client application informs the SSAI platform which sends a request to an ad decision server or ad server. The ad server evaluates various factors such as viewer demographics, content context, ad campaign settings, and advertisers’ real-time bidding (RTB) to select the most relevant ad(s) with the highest yield to insert.

  • Ad Stitching: Once the ad is selected, the ad server communicates with the SSAI platform responsible for ad insertion. The SSAI platform prepares the ad media via a dedicated conditioning workflow to match the source specification, and  dynamically stitches the designated ad(s) into the video stream by inserting the ad content into the original video stream at specified ad break points marked by SCTE markers / cue points.

  • Content Delivery: The video stream with the stitched-in ad(s) is then delivered to the viewer's device. The SSAI platform may use a CDN or edge servers to distribute the ad-stitched stream efficiently.

  • Seamless Playback: The viewer's video player receives the ad-stitched stream and seamlessly plays back the video content along with the inserted ad(s). From the viewer's perspective, the ad insertion appears as a natural part of the video, with no buffering or interruptions caused by ad loading, leading to a broadcast-grade premium viewing experience. In addition, overlays like countdown and number of ads can be shown on the player.

  • Tracking and Analytics: Throughout this process, SSAI platform and ad server track ad impressions, ad completions, and viewer interactions (e.g., clicks) to provide analytics and reporting to publishers and advertisers. This data helps optimize ad targeting, ad placement strategies, and overall ad campaign performance. For example, reporting system tracks, among the other metrics, active streaming sessions for a given period, channel, or platform, together with ad place opportunities, inserted ads, and completed ad views.

  • Ad Insertion Control: Media owners have centralized control over ad insertion and decisioning parameters, including ad frequency, ad podding (grouping of ads), exclusion, and targeting rules. Ad insertion policies can be dynamically adjusted based on real-time analytics and campaign performance metrics.

georg senzenberger
“The ecosystem of server-side ad insertion (SSAI) is highly complex and involves different partners for the best monetization possible. Besides numerous technical integration partners, there are almost the same amount of standards and formats. This requires strong partnerships between the server-side ad insertion providers, the ad servers, and the supply-side platforms (SSPs), and as well for the player and client-side beaconing (CSB) SDK to achieve a seamless integration and best performance. This strong basement is crucial for fine tuning in increasing the yield for contextual advertising or socio-demographic targeting. To maximize monetization, enriching request data to ad servers is essential, but this must be balanced with the strict protection of each user's data privacy”. - Georg Senzenberger, Nowtilus Head of Product and Platform

What are the technical requirements for implementing SSAI?

a hand touching a screen to set ssai requirements

Implementing Server-Side Ad Insertion (SSAI) requires platform operators to meet specific technical requisites to ensure successful integration and usage. Here we listed the key technical requirements for video publishers to deploy SSAI:

  • Video Content Preparation: Ensure that your video content is encoded in compatible formats (HLS or MPEG-DASH) suitable for streaming and ad insertion. Then deploy a robust CDN to efficiently deliver video streams and ad-stitched content to viewers with low latency and high availability.

  • SSAI Platform Integration: Choose a reliable and adaptable SSAI vendor capable of dynamically inserting ads into video streams based on different ad server requests like As a broadcaster, make sure to apply the supported SCTE ad markers into your content stream. Then integrate with the SSAI provider's APIs to facilitate communication between the video player/client, the ad server, and the SSAI platform for seamless ad insertion.

  • Ad Server Integration: Configure integration with one or more video ad servers (e.g., Equativ, FreeWheel, Magnite, Invidi, etc.) to handle ad decisioning and ad selection based on context, viewer data and campaign parameters. To be able to do that, ensure that your content stream is compatible with VAST (Video Ad Serving Template) and VMAP (Video Multiple Ad Playlist) standards.

  • Video Player Support: Use a video player that supports SSAI and can handle ad-stitched video streams seamlessly without interruptions like Castlabs, THEOplayer, Bitmovin, Viaccess-Orca, etc. Then consider integrating client-side SDKs (Software Development Kits) provided by the SSAI platform into the video player/application for advanced ad tracking and additional features like ad skipping prevention, ad-infos and interactivity.

  • Analytics and Reporting: Implement your event tracking system to capture ad impressions, ad completions, clicks, and other viewer interactions for analytics and reporting and/or rely on a comprehensive SSAI solution like that provides these metrics itself. 

  • Compliance and Security: Implement content protection measures to secure video streams and prevent unauthorized access or distribution, utilizing DRM (Digital Rights Management) platforms like Playready, Widevine, FairPlay, or use encrypted HLS. At the same time, be compliant with privacy regulations like GDPR for Europe and CCPA for the US when collecting and processing viewer data for ad targeting and analytics. To do that, Nowtilus customers usually operate with popular Consent Management Platforms (CMPs).

denis hoehne
“At Nowtilus we always ensure that the sources provided by our customers for live and video on demand are compatible with our software and we provide them punctual feedback on what to adjust. Once this is done, we analyze the sources again and perform tests in our test and productive environments. Nothing is left to chance.” - Denis Hoehne, Nowtilus Director of Operations

How does SSAI handle ad targeting and personalization?

a targeted tv screen

Server-Side Ad Insertion (SSAI) enables sophisticated ad targeting and personalization by leveraging viewer data and real-time decision-making capabilities. Here's how SSAI handles ad targeting and personalization.

  • Ad Decisioning Process: When a viewer requests video content, the video player or client application asks the SSAI solution to send a request to an ad server. With Prefetching enabled such requests can also be managed ahead of time allowing better performance due to higher fillrates. The ad server performs ad decisioning, which involves evaluating various parameters such as viewer demographics (age, gender, location), device type, browsing history, contextual data (content category, time of day), and advertisers’ real-time bidding (RTB). Based on this evaluation, the ad server selects the “winning” ad(s) to be inserted into the video stream (the most relevant ones with the highest yield that won the advertising auction).

  • Dynamic Ad Insertion: The selected ad(s) are then dynamically inserted into the video stream by the SSAI platform before being delivered to the viewer's device. Ad stitching occurs server-side, seamlessly integrating the ads into the video content without interrupting playback.

  • Personalized Ad Experiences: SSAI facilitates personalized ad experiences by delivering ads that align with viewer preferences and interests. In this context, not just the sponsored product but also ad creatives and messages can be customized via DCO (Dynamic Creative Optimization) to enhance relevance and increase the likelihood of engagement and conversion.

  • Real-Time Updates and Optimization: SSAI enables a dynamic process that allows real-time updates and optimizations to ad targeting parameters and campaigns. Ad campaigns can then be adjusted “on the go” based on viewer interactions, performance metrics, and changing market conditions to maximize effectiveness and ROI.

samuele macchi
""At Warner Bros. Discovery we are experiencing substantial revenue growth thanks to targeted dynamic advertising in our linear TV channels. By delivering personalized ads directly, we ensure that advertisements stay highly relevant for the addressed households. This targeted approach not only enhances viewer engagement and satisfaction but also maximizes ad effectiveness, leading to higher conversion rates and — subsequent — increased advertiser spending." - Samuele Macchi, Technical Director Digital Advertising Services - EMEA at Warner Bros. Discovery

How does SSAI handle ad podding and frequency capping?

tv screen showcasing ad podding

In collaboration with Ad Servers and SSPs, Server-Side Ad Insertion (SSAI) offers robust capabilities for managing ad podding and frequency capping, which are essential aspects for optimizing the ad experience within premium video content streams. But let’s see these two components in detail.

How SSAI handles ad podding

An ad pod is a group of ads sequenced in a row to be played back-to-back during a single ad break. TV publishers schedule ad breaks at strategic intervals and with specific durations within the video stream to ensure a balanced and legally regulated mix of content and ads. 

At the same time, SSAI platforms dynamically group the ads coming from the ad server into pods based on parameters such as ad length, ad slot requirements (e.g., pre-roll, mid-roll, post-roll), and viewer engagement metrics (by dynamically adjusting ad pod composition and scheduling based on real-time viewer interactions and behavior patterns). Then ad pods are seamlessly integrated into the video stream server-side, allowing for smooth transitions between content and ads.

How SSAI handles frequency capping

Frequency capping is the practice of limiting the number of times a viewer is exposed to a specific ad within a defined period. SSAI platforms facilitate frequency capping triggered by the ad-server, preventing ad overexposure (and consequent ad fatigue) while enhancing ad relevance. 

Platform operators can define frequency capping rules themselves based on viewer segments, ensuring that no viewer is subjected to the same ad excessively, or they can rely on the limits set by the ad server / SSP. Frequency capping policies are then followed by the SSAI platform, allowing for consistent ad delivery across different platforms and devices.

As stated before, SSAI platforms track ad impressions and viewer interactions in real-time so it is easy for them to monitor the effective ad exposure for the publishers to make the necessary adjustments where needed.

anne georgi
“Ad podding is an important mechanism to enable SSAI handling all ads for one break with one request only. The ad insertion experience is smooth, publishers can control their ad delivery more precisely and this leads to increased monetization. Frequency capping offers viewers variety whilst it also allows them to keep certain ads in mind. With that comes a huge improvement in user experience avoiding repetition and keeping the engagement of viewers high at the same time”. - Anne Georgi, Nowtilus Ad Operations Manager

What types of analytics and reporting are available with SSAI? ssai analytics

Server-Side Ad Insertion platforms offer comprehensive analytics and reporting capabilities to support content owners and advertisers in understanding ad performance, optimizing campaigns, and making informed decisions. 

These platforms can provide insights into ad impression and ad campaign performance, viewer engagement, audience demographics and behaviors, and quality of service metrics. SSAI enables real-time monitoring of ad delivery status and offers customizable dashboards for visualizing data and generating automated reports. 

Additionally, Server-Side Ad Insertion platforms facilitate integration with third-party analytics software, such as MediaMelon’s and IAB’s, to enable comprehensive reporting and analysis.

To give a concrete example of the metrics monitored by SSAI platforms, these are the main KPIs considered by and available in

  • Channel-Sessions: the active streaming sessions alongside the total number of sessions created for a given period/channel.

  • Ad Place Opportunities: the detected SCTE35 ad-markers within a live-source-stream, or the ad-cue points for a VoD playlist (mRSS) request.

  • Delivered Ads: the number of fulfilled ad deliveries, where the playback of a commercial reached at least the first impression.

  • Inserted Ads: the number of available ads that are inserted and ready to be streamed for the full stream

  • Completed Ad Views: the number of fully-watched commercials.

  • Ad Views Ratio: the percentage of an ad that has been watched, tracking user engagement through segments such as first quartile, midpoint, third quartile, and completion.

  • Ad-Campaign View Completion Rate: the ratio between the inserted and started ad campaigns and the fully watched ones.

mohammad hammoud
“The detailed analytics provided by SSAI platforms, such as, empower users with a comprehensive understanding of their ad performance, enabling real-time adjustments and long-term strategic planning. This level of insight ensures that advertising efforts are both efficient and effective, meeting the evolving needs of publishers and advertisers.” - Mohammad Hammoud, Nowtilus Lead Full-Stack Engineer

Is SSAI secure and compliant with industry standards and regulations such as ISO, GDPR and CCPA?

touch screen with iso 9001 symbol and a hand touching it

Server-Side Ad Insertion (SSAI) platforms strive to comply with industry standards and regulations, including data privacy laws such as the General Data Protection Regulation (GDPR) in Europe and the California Consumer Privacy Act (CCPA) in the United States (besides other states who also strive towards privacy enhancements). Compliance with these regulations is essential to protect viewer privacy and ensure responsible data handling practices within the context of ad serving and audience targeting. Especially in an era with lots of uncertainty around how walled gardens handle privacy issues, it is fundamental to provide answers to the increasing concerns that viewers have around the world. Here's how SSAI platforms typically address data privacy requirements:

  • Transparency and User Consent: SSAI platforms provide clear information about data collection, processing practices, and data handling policies. Utilizing Consent Management Platforms (CMP), users can make informed decisions about their data privacy preferences, supported by transparent disclosures in privacy policies and terms of service. This approach ensures people have visibility into how their information is used for ad serving and can exercise their rights related to data access, correction, and deletion.

  • Data Minimization and Anonymization: Data minimization is prioritized by collecting and processing only necessary data for ad targeting and measurement purposes. At the same time, personally identifiable information (PII) is anonymized or pseudonymized to protect user identities and privacy.

  • Security Measures: SSAI platforms implement robust security measures to safeguard user data against unauthorized access, breaches, or misuse. Encryption, access controls, and data retention policies are employed to protect data integrity and confidentiality.

  • Compliance Audits and Certification: Many SSAI companies undergo regular compliance audits and may obtain certifications to demonstrate adherence to privacy regulations and security best practices. Compliance with industry standards such as IAB (Interactive Advertising Bureau) guidelines for ad tech companies is also prioritized. is a certified IAB Tech Lab member and our platform has a SSAI Pentest rating of A+ with Astra Security. We are also working towards an ISO-27001 certification to further prove our regular commitment to users’ privacy and security.

  • Adherence to Regulatory Requirements: Regulations are an always evolving field, so SSAI vendors constantly adapt their practices to align with the newest regulatory requirements and recommendations from data protection authorities. Compliance teams monitor changes in privacy laws and ensure ongoing adherence to legal obligations.

shikhil sharma
“In today’s digital advertising landscape, the security of SSAI platforms is paramount. These platforms handle vast amounts of sensitive data and play a critical role in delivering personalized ad content. As such, maintaining stringent security measures and compliance with industry standards is essential to protect against potential cyber threats and data breaches. has obtained A+ in Astra Security pentest rating. This achievement underscores the company's commitment to implementing best-in-class security practices, including robust encryption, access controls, and comprehensive data protection measures.” - Shikhil Sharma, CEO at Astra Security (cyber security company)

How to choose the best SSAI solution?

woman watching a tv screen with dynamic ad insertion by

Choosing a Server-Side Ad Insertion Solution is not an easy task as this choice is directly connected with the monetization potential of a streaming platform / OTT video publisher.

The decision-makers in those companies have to consider several key factors based on the points we analyzed in the previous paragraphs but not limited to those.

Generally speaking, when selecting an SSAI solution prioritize platforms that have the following attributes:

Efficient manifest manipulation

Efficient manifest manipulation is key in SSAI. It enables dynamic modification of video manifests for seamless ad insertion, reducing latency without requiring additional client-side requests or delays, and offering precise control over ad placement (e.g., pre-roll, mid-roll, post-roll) and ad durations. Optimized manifest manipulation clearly enhances the scalability of SSAI solutions. By efficiently managing manifest modifications on the server side, platforms can handle large volumes of ad requests and concurrent viewers without performance degradation. This scalability is essential for delivering ads seamlessly across multiple devices and ensuring consistent ad delivery under varying traffic conditions.

VAST compliance

While not all aspects of SSAI directly involve VAST (especially when considering server-side ad stitching and delivery), VAST compliance is crucial for facilitating the interaction between SSAI platforms and ad servers, ensuring proper ad delivery, tracking, and measurement within video content streams. This adherence to industry standards enhances the overall effectiveness and efficiency of SSAI implementations in digital advertising workflows.

Flexibility and integration 

An SSAI platform that is, as far as possible, technology-agnostic and able to answer to the different and evolving customers’ requirements is definitely preferable in a fast-changing environment like MediaTech.A software that is customizable and easily adaptable to your existing streaming infrastructure, CDN, ad server(s), and SSP(s) will definitely save your tech department precious time (and headaches)! Also ensure that the chosen solution is compatible with various devices and platforms (CTVs, set-top boxes, apps, web, mobile, etc.).Existing integration with major ad-networks will further increase the efficiency of set-up and processes.

Industry trends and innovation

For a TV operator or publisher, selecting an SSAI vendor with a sharp focus on innovation is crucial in maintaining a competitive edge and delivering a superior viewer experience. An innovative SSAI vendor stays ahead of industry trends, continuously integrating new technologies and adapting to changing consumer behaviors. Speaking about emerging technologies, for example, you should keep an eye on the developments of Dynamic Ad Substitution in Broadcast, utilizing HbbTV in Europe and ATSC 3.0 in the US (now renamed to “NextGenTV”). Also observe Server-Guided Ad Insertion (SGAI) which combines the advantages of SSAI and CSAI to provide a more efficient ad delivery process, and DCO (Dynamic Creative Optimization) which dynamically customizes ad components, such as images, text, and calls-to-action, to create tailored creatives that are highly relevant to individual viewers. Also GenAI will heavily influence the creation and delivery of video ads short term.

Security and privacy compliance

When selecting an SSAI solution, also bear on the top of your mind both security and privacy compliance. Opt for a platform with robust security measures, including encryption, access controls, and data retention policies, to safeguard user data and ensure reliable ad delivery. Make sure that the SSAI solution prioritizes privacy compliance by adhering to regulations like GDPR and CCPA. Look for platforms supporting robust user consent management, data minimization practices, anonymization of personally identifiable information (PII), and transparent data handling practices to protect user privacy and build trust with viewers. 

Apart from these 5 pillars, always pay attention to the vendor reliability and industry reputation, the quality of the customer support, and the pricing model that should always be transparent and based on usage, ad impressions, or other definable metrics. has a simple pricing structure with a transparent CPM model, reflecting regional differences in the CPMs achievable by publishers, without additional costs for infrastructure or bundled product prices. Our solution is VAST compliant and rated A+ for security, technology agnostic, and pre-integrated with top-tier ad-networks.

In addition to that, we cooperate actively with the most important technology consortiums and research institutes such as IAB Tech LAB and Fraunhofer FOKUS to always be one step ahead regarding quality and innovation. To give a concrete example, we are already working to integrate the rising solutions we mentioned in this paragraph into our offering in combination with our cutting-edge HbbTV DAS (Dynamic Ad Substitution) thanks to which we leverage the broadcast and the digital world together, holistically serving tier 1 customers in their whole product portfolio.

For these reasons, large TV players like Warner Bros Discovery, Deutsche Telekom MagentaTV, and A1 Austrian Telekom are already counting on our SSAI platform.

Contact us if you want to know more about how we prioritize the different aspects of Server-Side Ad Insertion and Dynamic Ad Insertion underlined in this article.

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