What Is SGAI (Server-Guided Ad Insertion)?

SGAI is a next-generation ad delivery architecture for streaming video that combines the best of SSAI and CSAI. The server signals ad break opportunities through the content manifest while the client-side player handles actual ad resolution, insertion, and measurement on-device.

Server-Guided Ad Insertion, commonly known as SGAI, represents a fundamental shift in how streaming platforms deliver advertising. Unlike older methods where the server either stitches ads into the video feed (SSAI) or the client downloads and plays ads independently (CSAI), SGAI takes a hybrid approach.

The origin server creates a content manifest containing SCTE-35 markers that signal where ad breaks can occur. This manifest is not viewer-specific, which means it can be cached at the CDN layer for efficient delivery to millions of simultaneous viewers. When a viewer's device reaches an ad break marker, it sends a personalized ad request to the ad decision server, including targeting parameters like device type, geography, viewing history, and real-time contextual signals. The ad decision server responds with the optimal ad creative, and the player handles insertion and playback locally on the device.

This architecture delivers three critical advantages simultaneously: broadcast-quality playback without buffering or latency (because the manifest is cached), granular personalization (because ad decisions happen per-viewer in real time), and accurate client-side measurement (because the player controls ad rendering and can fire impression beacons precisely).

For live sports specifically, SGAI enables inserting ads during natural breaks in the action — timeouts, pitching changes, substitutions, halftime — without the 15-30 second delay that SSAI typically requires. Google's Early Ad Break Notification API facilitates this by sending advance signals to the player before a live ad break occurs.

How Does SGAI Differ from SSAI and CSAI?

SGAI bridges the gap between SSAI's seamless playback and CSAI's real-time personalization, delivering the strengths of both without either technology's primary drawback.

CSAI (Client-Side Ad Insertion) was the original approach to digital video advertising. The video player on the viewer's device requests ads independently and plays them between content segments. CSAI offers excellent personalization and accurate measurement through client-side beacons. However, ad blockers can intercept and block ad requests, transitions between content and ads often produce visible buffering, and the approach struggles on CTV devices where player capabilities vary widely.

SSAI (Server-Side Ad Insertion) emerged to solve these problems. The ad server stitches ad creatives directly into the video stream on the server side before it reaches the viewer. From the player's perspective, the ad-enhanced stream looks like a single continuous video — no buffering, no visible transitions, and ad blockers cannot distinguish ads from content. Its weakness is personalization and measurement.

SGAI bridges both approaches. The server guides ad opportunities through the manifest (like SSAI), but the player resolves and renders ads client-side (like CSAI). You get SSAI's seamless playback with CSAI's personalization and measurement.

Why Is SGAI Gaining Adoption in 2026?

SGAI adoption is accelerating because live sports streaming has exploded and platforms need ad insertion technology that can monetize live content at scale without degrading viewer experience.

Nearly 85% of all ad revenue from subscription OTT services now comes from connected TVs, according to MNTN Research. Live sports rights spending has more than doubled from $6.5 billion in 2022 to a projected $14.2 billion in 2026.

Disney+ deployed SGAI at scale, demonstrating that the technology works for major streaming platforms with tens of millions of concurrent viewers. Google integrated programmatic advertising capabilities with SGAI-native platforms, enabling real-time bidding within SGAI ad breaks.

The economic argument is equally compelling. SGAI's cached manifest architecture dramatically reduces CDN costs compared to SSAI, which requires unique server-side stitching for every viewer session.

What Ad Formats Does SGAI Support?

SGAI enables a significantly broader range of ad formats than traditional pre-roll or mid-roll insertions, including interactive elements, overlays, and non-standard placements that SSAI cannot support.

In-Play Overlay Ads appear as native overlays during live content without interrupting the video. These are triggered by real-time events — timeouts, pitching changes, substitutions — and display contextually relevant brand experiences.

Pause Ads activate when a viewer pauses the stream. TripleLift found 100% viewability with 24-second average dwell time and 91% aided brand recall.

L-Bar and Side-by-Side Ads reduce the content window to display an ad alongside the live stream.

Shoppable Ads integrate transaction functionality directly into the ad experience, enabling viewers to purchase products without leaving the stream.

Interactive Ads use gesture-based controls to let viewers engage with ad content. Engagement rates consistently outperform standard pre-roll by 3-5x.

Who Are the Leading SGAI Technology Providers?

The SGAI ecosystem includes full-stack platforms, player SDK providers, and infrastructure companies — with StreamLayer, InTheGame, Wowza, Bitmovin, Castlabs, and Google being key players.

StreamLayer pioneered AI-powered SGAI with a proprietary Event Trigger Engine that analyzes live video data in real time to identify optimal ad insertion moments. Their Google programmatic integration enables real-time bidding within SGAI ad breaks.

InTheGame (ITG) offers SGAI technology with native platform plugins and Picture-in-Picture implementations.

Wowza provides streaming infrastructure with SGAI support. Bitmovin and Castlabs offer video player SDKs with SGAI capabilities. Google provides the programmatic demand side with their Early Ad Break Notification API.

How to Evaluate an SGAI Platform

When selecting an SGAI technology partner, evaluate five key dimensions: live event support, cross-device rendering, programmatic integration, measurement accuracy, and scalability.

Can the platform detect and respond to real-time events during live broadcasts? Does the SGAI implementation deliver consistent, broadcast-quality ad experiences across CTV, mobile, web, and tablet? Can it connect to major ad exchanges and DSPs for real-time bidding? Does it provide accurate client-side measurement? Can it handle peak concurrent viewership during major live events without degraded performance?

What Does the Future of SGAI Look Like?

SGAI is in its early adoption phase, but as live sports streaming grows (projected 21% increase in U.S. live sports streamers by 2027) and CTV advertising investment accelerates (54% of marketers plan to increase CTV spend in 2026, per Kantar), demand for SGAI will intensify.

The next frontier includes AI-driven ad creative optimization, cross-platform frequency management, and deeper integration with retail media networks.

Frequently Asked Questions

Is SGAI better than SSAI?

SGAI addresses two key limitations of SSAI — limited personalization and poor measurement — while retaining SSAI's advantages in playback quality and ad blocker resistance. For live content monetization and programmatic demand, SGAI is the superior choice.

Does SGAI work with ad blockers?

Yes. The content manifest containing ad break markers is indistinguishable from the regular content manifest, so ad blockers cannot identify and block SGAI ad requests.

Which streaming platforms use SGAI?

Disney+ has deployed SGAI at scale. Multiple sports streaming platforms including those powered by StreamLayer use SGAI for live event monetization. The technology is also seeing adoption in FAST channels and major OTT platforms.

How does SGAI handle live sports latency?

SGAI avoids the 15-30 second delay typical of SSAI in live scenarios. By using pre-signaled manifest markers and Google's Early Ad Break Notification API, SGAI platforms can insert ads within milliseconds of a live event trigger.