Server-Guided Ad Insertion (SGAI) and the Future of Streaming
What is server-guided ad insertion (SGAI) from a technology standpoint; how does it differ from client-side ad insertion (CSAI) and server-side ad insertion (SSAI); how does it impact or change existing streaming workflows, infrastructure, and delivery; and what benefits does it provide to streaming publishers, advertisers, and viewers? Bitmovin senior director of product management James Varndell and Ring Digital, LLC principal analyst Brian Ring break down SGAI, its advantages, and a key emerging use case in this discussion from Streaming Media Connect 2026.
SGAI Compared to CSAI and SSAI
Ring opens the conversation by defining SGAI. With CSAI, the publisher controls and exploits all of the data and does real-time bids. “They can integrate Google IMA SDKs that’s going to help fill, but they buffer, they can be blocked, they suck a lot of resources on the player,” he cautions. So then SSAI became popular, which allows publishers to insert ads on the server side to provide a “seamless TV experience, therefore tapping more money. The movement of linear into digital is all about that. But you do have, I think as a publisher, a little less control. There’s more complexity. There’s more gatekeepers essentially into how we can get this done,” Ring notes.
He believes SGAI “is the best of both worlds” because it’s hybrid. “You get the client-side control and then you get the market of the server side.” He asks Varndell for his interpretation of SGAI and how it affects the future of streaming.
Varndell likes “hybrid ad insertion” as a comparable term for SGAI. “So you’re right, publishers with SGAI still have the control to signal ad breaks on the server side, but also the player has an element of control over how each ad is actually presented to the viewer. So you’re taking the best aspects of that from the player side, from [CSAI], but without requiring the player to do all of the ad scheduling work,” he explains, which can be challenging for video players on CTV devices. In instances where there’s a single decoder, Varndell says as an example, “the player’s trying to do everything, including ad and content transitions, as well as scheduling with CSAI. So SGAI avoids putting that load onto the player, but also you’re taking some of the best things from SSAI in terms of making the ad experience seamless within the content, choosing the optimal timing around ad breaks on the server side.”
SGAI Approaches, Such as Double Boxes
SGAI enables the integration of technologies such as AI for contextual ads, Varndell says, bringing streaming services advantages and value. “HLS Interstitials is one of the formats that enables SGAI. And I think in terms of some approaches we are seeing our customers taking today, [one] is actually starting with a transition towards SGAI that’s quite transparent to viewers. … [Y]ou can implement SGAI using HLS Interstitials [so] it provides the same experience as [viewers] currently get with [CSAI or SSAI].” Varndell is optimistic about ad formats such as squeezebacks, L-bars, and double boxes, but those don’t need to be options “to still get some benefits from SGAI and some quite important advantages of that HLS Interstitials format. So [you can be doing] things like maybe personalizing ads within a DVR window in a live stream or gaining some kind of cost reductions from SGAI, but still providing the viewers with the same experience, and then you’ve got the infrastructure in place to start to experiment with those new ad formats.”
Ring replies, “I love that you brought up the DVR window. So it is an ad workflow technically, but it’s really more on the infrastructure side about how [to] deliver it. It’s not about how we hook into the programmatic flows and things like that.” He talks a little about data he’s collected over the years, noting that “people do not mind ads at all unless they’re really disruptive,” so something like a double box is “a key kind of innovation,” Ring says.
The Effective Use Case of Double Boxes
Varndell says double boxes are “a particularly cool use case” and sets out to explain: “So for example, maybe you’re at home or you are running errands, you’re keeping track of a live sports game. … Maybe your friends are messaging you about it, you’re keeping track of the score on ESPN or something. And then something exciting happens in the game. Maybe it’s close to the end of the game, there’s a close score, or—we’ve got the World Cup coming up this summer—penalty kicks [are] awarded, for example. You open your streaming service, you choose to watch the live game, but immediately you see two to three minutes of ads, and that can be really frustrating as a viewer because you’ve specifically loaded the game and loaded your streaming app to watch this critical moment, but you can’t see it.”
By the time the ads are over, the exciting part of the game might be too, he says, citing the example of an app that Bitmovin is involved with that notifies users when a game is getting close to the end and the score is tight. “And when users tap on that notification to watch the game, rather than seeing a two- or three-minute ad, they actually see a double box with the game at its exciting conclusion with an ad alongside. So I think that’s a really cool use case,” Varndell says. “Everyone’s a winner. The publisher is a winner because they’re getting the viewer into their app and it’s really given them a lot of confidence to proactively tell their viewers that something exciting is happening and they should tune in.” The viewer is a winner because they don’t miss the end of the game, and the advertiser and the brand win too “because they’re showing an ad at a point where viewers are paying close attention to the screen, and that’s quite a valuable moment that they can monetize.”
Join us May 12–14, 2026 for more thought leadership, actionable insights, and lively debate at Streaming Media Connect 2026! Registration is open!
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