Tim Sewell
CEO, Yospace
Yospace has been a leader in dynamic ad insertion (DAI) technologies for 14 years. As a result, we're frequently asked about the latest innovations in this space. A common question we’ve been asked this year is: "What is server-guided ad insertion and how does it differ from SSAI?" This article answers that question and more.
We’ll break down the three most popular types of ad insertion used in modern streaming:
We’ll explain what each method does, where it performs best, its limitations, and offer guidance on how to maximise dynamic ad insertion's revenue potential.
Dynamic ad insertion (DAI) is a strategy for delivering advertisements into video content, both in video-on-demand (VOD) and live streaming environments. It helps broadcasters and streaming platforms increase advertising revenue by targeting viewers with relevant ads while maintaining an uninterrupted user experience.
Here are the ways in which dynamic ad insertion is executed.
With CSAI, the video player (or "client") is responsible for pausing the content, fetching an ad from an ad server, playing the ad, and then resuming the main video.
SSAI shifts the ad insertion process to the server. Ads are stitched directly into the content before it reaches the user, creating a single continuous stream.
However, Yospace solves the measurement issue with:
SGAI represents the next evolution in dynamic ad insertion. Built on HLS Interstitials and MPEG-DASH Events, it divides responsibilities between the server and the client to provide a more efficient ad insertion solution. With SGAI, the server identifies ad opportunities and sends signals to the client to fetch and play ads.
This next phase of DAI is the first based on industry standards. It offers benefits such as lower server load, enabling better monetisation of VOD and extended DVR windows, as well as a broader range of ad formats.
At NAB Show 2025, Yospace showcased SGAI with new side-by-side ad formats and support for dynamic ad insertion during extended DVR windows — whereby ads viewed when a viewer scrolls back a live stream are replaced. This addresses a 12% live viewer segment that often goes unmonetised.
Formats like L-shaped banners and in-screen ads are possible today with SSAI, but they require bespoke client-side development. Today SGAI does not necessarily support these features “out of the box,” but in time, it will simplify implementation considerably.
*Various DAI vendors offer different solutions. Best practice is to offer SSAI and/ or SGAI combined with client-side measurement, so broadcasters get the best of both worlds.
While SGAI and SSAI are highly effective, they are only part of the solution as neither fully resolves the issue of scaling DAI to large audiences, particularly during unpredictable live events.
This surge of ad calls can overwhelm SSPs and ad servers, resulting in missed ad opportunities and revenue losses.
The solution is intelligent prefetch systems that pace ad requests to prevent server overload, reduce timeouts and ensure high-value ad inventory is filled and its value is maximised.
Whether you're deploying SSAI or SGAI, a prefetch strategy is crucial for reliably scaling dynamic ad insertion.
The term server-guided ad insertion, or SGAI, can mean different things to different people. SGAI is built upon the latest standards in HLS Interstitials and MPEG-DASH Events, which focus on stream stitching. However, these new additions don’t enable a standard method of ad measurement.
In order to build trust with advertisers, IAB-compliant measurement of ad views is a must. Best practice is to ensure that SGAI (or SSAI) is accompanied by a lightweight SDK that delivers client-side measurement. SDKs require control of the player, which is not always possible. This is often the case with syndicated channels across third-party endpoints.
Adoption of the new Common Media Client Data v2 (CMCDv2) standard addresses the third-party distribution issue. CMCDv2 delivers low-level playback information to the server-side, which the DAI system can convert into the measurement advertisers require.
SGAI is generating significant excitement within the industry, but it's important to recognise that this is more of an evolution than a revolution. While SGAI refines ad insertion techniques, it doesn't fundamentally change the landscape. Instead, it optimises the existing approaches to make ad insertion more flexible, efficient, and cost-effective for future-proof ad monetisation.
There are many factors to consider when choosing the best dynamic ad insertion strategy for you, including:
DAI is a technology that enables real-time, personalised adverts to be inserted into live or on-demand video content.
CSAI inserts ads on the client side, offering detailed tracking, but is vulnerable to ad blockers. SSAI stitches ads server-side for smoother playback and better ad blocker resistance.
SGAI is a new evolution of DAI. It is a hybrid approach where the server identifies ad slots and guides the client to fetch and play ads. It balances tracking, playback quality, and scalability.
SGAI shares responsibilities between the server and the client, enabling real-time ad resolution and increased flexibility in playback. In contrast, SSAI handles all ad stitching server-side before the stream is delivered. SGAI typically supports more dynamic use cases and enables cost-effective scaling, especially for live and VOD content.
