Connected TV (CTV) advertising is projected to reach $40 billion globally in 2026, and the technology used to insert ads into OTT streams directly affects revenue. Two architectures dominate: Server-Side Ad Insertion (SSAI), the established approach, and Server-Guided Ad Insertion (SGAI), the emerging standard that promises to combine the best of server-side and client-side approaches.
SSAI: The Established Standard
SSAI stitches ad creative directly into the video stream on the server before delivery to the viewer. The player receives a single, seamless manifest containing both content and ads. From the viewer's perspective, it looks identical to broadcast television — no ad loading delays, no buffering between content and ads, and complete immunity to client-side ad blockers.
- Pros: Seamless viewer experience, ad-blocker proof, simple player implementation, universal device compatibility
- Cons: Higher server-side processing cost, limited ad personalisation granularity, transcoding overhead for ad creative matching
SGAI: The Next Evolution
SGAI takes a different approach: instead of stitching ads server-side, the server provides guidance to the client player on exactly when and where to insert ads. The player handles the actual ad rendering, enabling richer ad formats (interactive overlays, companion ads, L-shaped frames) that SSAI cannot support.
SGAI also enables frame-accurate ad replacement in live streams — a critical capability for simulcast ad monetisation where broadcast ads need to be replaced with personalised digital ads in real time.
- Pros: Interactive ad formats, frame-accurate live replacement, lower server cost, per-viewer personalisation
- Cons: More complex player implementation, requires SGAI-compatible players, newer technology with fewer implementations
Which Should Operators Choose?
The answer depends on the use case. For FAST channels and VOD, SSAI remains the pragmatic choice — it works with every player on every device and requires minimal client-side complexity. For live sports with simulcast ad replacement, interactive ad experiences, and premium CTV inventory, SGAI delivers superior monetisation potential.
MwareTV's TVMS supports both SSAI and SGAI ad insertion, allowing operators to deploy the right technology for each content type. The platform integrates with major ad exchanges (Google Ad Manager, FreeWheel, Magnite) for programmatic demand and supports direct-sold inventory management.
