FAST has created even more interest in DAI technologies than ever before, but with HbbV TV and ATSC 3.0 just around the corner, things could get even more interesting in the near future, writes John Maxwell Hobbs.

The dramatic increase in the rollout of FAST (Free Ad Supported Television) channels has presented new opportunities and challenges for channel owners and advertisers. This has resulted in an increased focus on the use of Dynamic Ad Insertion (DAI) technology to enable personalised and targeted ads. Real-time bidding (RTB) platforms and programmatic advertising have facilitated the efficient delivery of targeted ads, ensuring that advertisers can reach their desired audiences with precision.


DAI can be delivered in two ways, Server Side Ad Insertion (SSAI) and Client Side Ad Insertion (CSAI).

Each approach has its own set of advantages and disadvantages:

Dynamic Ad Insertion - Server Side Ad Insertion (SSAI):


  • 1. Seamless User Experience: SSAI pre-fetches and stitches ads into the content stream on the server side. This eliminates buffering and latency issues that can disrupt the viewer’s experience, resulting in a smoother transition between content and ads.
  • 2. Ad-Blocker Resistance: Ad-blocking software typically targets client-side ad requests, making it less effective against server-side inserted ads.
  • 3. Dynamic Ad Replacement: Ads can be swapped out and updated in real-time. This enables advertisers to deliver targeted and up-to-date ads to viewers, maximising the relevance and effectiveness of their campaigns.


  • 1. Lack of Personalisation: Since ads are inserted on the server side, SSAI relies on broad targeting parameters rather than granular user data. While this approach still allows for some level of targeting, it may not provide the same level of personalisation as CSAI.
  • 2. Limited Reporting and Analytics: Since ads are inserted server-side, it may be difficult to obtain precise metrics on ad viewability, completion rates, and user engagement. This can limit advertisers’ ability to measure the success of their campaigns accurately.

Dynamic Ad Insertion - Client Side Ad Insertion (CSAI):


  • 1. Enhanced Personalisation: CSAI allows ad decisions to be made on the client side, leveraging user data and real-time targeting.
  • 2. Robust Reporting and Analytics: CSAI provides detailed metrics and analytics, allowing advertisers to measure ad viewability, completion rates, click-through rates, and other valuable insights.
  • 3. Flexibility and Control: CSAI allows content providers and advertisers to have more control over ad placement and creative elements. Advertisers can experiment with different ad formats, placements, and frequency capping to find the most effective approach for their campaigns.


  • 1. Potential Disruptions: CSAI can result in buffering and latency when ads are being loaded on the client side. These interruptions can be frustrating for viewers and may lead to user disengagement or abandonment of the content.
  • 2. Vulnerability to Ad-Blockers: Ad-blocking software can detect and block client-side ad requests, leading to a loss of ad revenue for content providers and advertisers.

Read more The pursuit of personalisation and the evolution of dynamic ad insertion

Dynamic Ad Insertion - Client Side

Johan Bolin, CTO, Agile Content has seen the most significant recent developments happening in CSAI technologies.

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Johan Bolin, Agile Content

“In last two years, there have been some improvements in some protocols, especially in MPEG-DASH that have made things a little bit easier when it comes to doing the actual ad insertion,” said Bolin. “For example, in MPEG-DASH you can now use templated manifests in combination with ad insertion.”

Another recent change is with HLS (HTTP Live Streaming). “Apple have introduced the concept of having double players, meaning that you can essentially signal the ads separately to the content and preload the ads in one of the players while you are playing the content in the other player,” he said.

“And when there is time for an ad break in the device, you can do a very nice shift from one player to the other. It means that the shift over from the content to the ad can be done more smoothly.”

Dynamic Ad Insertion - Server Side

Depending on the application, SSAI can be more cost effective in delivering ads. “FAST is creating cost efficient, well-segmented TV channels based on interest groups,” said Bolin. “You could create a cooking channel for British food. It’d be difficult to do that in traditional broadcast domain simply due to the high costs associated per channel, if you do it in streaming, you can create it at a significantly lower cost. The pure fact is that you can create these kinds of niche content channels at a very, very cost-efficient level.”

“You could obviously deliver ads in the player (CSAI). The flip side of that is that you have a lot of player dependencies. It might not work on all devices. It will definitely not work in all streaming formats, so older Smart TVs will be a huge problem.”

As opposed to VOD, FASTs replicate traditional broadcast scheduling, with viewers watching the same programme at the same time which presents challenges to the CSAI approach.

“If you aggregate a lot of audience at the same point in time, then that is difficult to do on the client side because you need to figure out a way to signal and synchronise clients and so on,” said Bolin.

“It’s easy if you do it on the network side. On the network side, you have three alternatives: you can use manifest based stitching, which is the technology that is most common today for ad insertion. Or you could stitch segments in the packager - it’s zero cost per viewer.

“The third way is to do it on the encoder, which is similar to classical broadcasting. Even if you do it only for streaming, it’s cheaper than doing it in playout because you don’t have all the distribution costs associated with it.”

Dynamic Ad Insertion - Privacy

Privacy has become an increasing concern for viewers, and the EU’s introduction of GDPR (General Data Protection Regulation) has required changes to the technologies underpinning DAI systems.

Valentijn Siebrands_Solutions Architect_M2A Media (1)

Valentijn Siebrands, M2A Media

“Before GDPR, you could signal rather detailed information about the actual viewer to a third-party decision server,” said Bolin. “The result of that was that the company you signal this to could gather this information and get a decent idea of the subscriber and the ads could be very, very personalised.

“I think pretty much in parallel to GDPR, there’s also been a bit of pushback from the viewers. If you’re doing dynamic ad insertion too well the viewer feels that it’s beyond the level of acceptance for how granular you are allowed to slice the ads.”

“Nowadays, you anonymise the data,’ he explained. ‘You have a lot of data from a viewer, and before it leaves your work distribution domain you remove all data that can be associated with a particular individual. Then you map that into a kind of an interest metric that is sent as a signal to the ad decision server.”

Valentijn Siebrands, Solutions Architect at M2A Media highlighted user experience and sustainability issues around privacy and personalisation.

“GDPR doesn’t help service administration, because you cannot exchange as much data,” he said. “There are still ways to monetise content, but slightly different because you have to segment people before they login. Personalisation also means that the auction that takes place to show you one ad takes an enormous amount of compute power and an enormous amount of servers in order to get it on your device, which can also mean there will be technical glitches, because the chain is getting longer and longer. Therefore, the experience might be hard. It’s twofold: personalisation drives people to more control. And the other side is that it’s expensive.”

“But the difference is actually how much energy do you consume in order to get it?” he said. “And how much data and how many people are involved in order to gather all that data, in order to make the auction happen, and with a happy outcome to monetise it? And I think the honest answer is, unless AI is really going to help out, true monetisation and sustainability will define how this will work out in the future.”

Dynamic Ad Insertion – The future

Both Siebrands and Bolin believe that we have only scratched the surface of what’s possible with DAI, and that much more work needs to be done.

“We have to keep an eye on what is happening,” said Siebrands. “In America, you have ATSC 3.0, which is about mixing terrestrial with OTT, and the same is happening in Europe, everybody’s talking about HbbV TV (Hybrid Broadcast Broadband TV). I’m not saying HbbTV is not made for advertising, but it’s harder to do.”

Bolin feels that much more work needs to be done to change the essential nature of advertising. “I would like the TV industry and the advertising industry to spend more time trying to figure out how can we evolve the concept of advertising,” he said.

“I see plenty of untapped potential in using the fact that on the internet you have an interactive channel and you have a channel where you can use multiple devices and so on. If you do this the right way, there is a win-win - you could drastically improve the value of the inventory.

“By doing that you could reduce the ad load - maybe you could cut the number of ads per hour down by half. I think if we want to make something fantastic, we should ask the question, ‘what kind of new advertising concepts and products could we develop for streaming services that take advantage of the capabilities of the internet?’”

Read more Dynamic ad insertion: A win-win-win proposition?