SSAI vs CSAI: Server-side ad insertion or client-side ad insertion, which is best for my business?  

SSAI or CSAI? This is a good question to ask yourself when choosing a delivery method for your advertising-supported service. Bearing in mind that there are differences to consider, depending on whether you have live streams, VOD content, or both.

Advertising investment in the OTT market is projected to exceed $2 billion in 2022, with many of the largest streaming service providers adopting ad-supported tiers to provide viewers with a cheaper subscription or free-to-view tier. Advertising video-on-demand (AVOD) services are growing at a faster rate than subscription-based services, so it’s never been a better time to adopt an advertising-supported model.

When it comes to deciding on SSAI or CSAI for your ad-supported OTT service, there’s a lot to consider before you take the plunge on your chosen delivery method. Read on to find out which is best for your business ⬇️ ‍

What is SSAI and how does it work? 🍏

🍏 Server-side inserted ads are stitched directly into the stream, and they play out almost exactly like traditional broadcast channel ad breaks. It’s seamless, as the viewer isn’t waiting for the ad to load. The viewer’s content doesn’t pause, it’s a continuous viewing experience with no pauses or breaks between content and ads.

What is CSAI and how does it work? 🍊

🍊Client-side inserted ads are slightly different in that the content and ads are not stitched together. From the viewer’s perspective, the player will switch between the content and ads, and this change will be noticeable as the content they’re viewing will pause before the ads begin playing. The ads are being inserted by code on the device itself, resulting in a slightly less subtle transition from content to ads, with some latency.

It really is apples and oranges.

Targeted and relevant ads 🎯

Regardless of your chosen delivery method, both provide ads which are targeted and relevant to the viewer. This is a key benefit when compared to traditional broadcast channel ad slots, where you can’t be certain about who is watching. You can target by IP address - provided the viewer has given their consent for their data to be used in this way - meaning a higher CPM for the ads you serve due to the increased relevancy to the viewer.  

SSAI benefits 🚀

• Well-suited for linear and live streams, or VOD
• Instant deployment across multiple platforms – SSAI is deployed once on the backend and can be instantly applied to an unlimited number of applications  
• Prevents ad-blocking by seamlessly stitching ads into content  
• Supports insertion of ads over a linear slate, so no black screens  
• No SDKs required – totally codeless integration, no regular code updates required  
• Rich tracking and metrics for ad performance reporting  
• Programmatic ad requests, including targeting and consent data
• Adverts are transcoded on the fly into multiple renditions, to match the bitrates of the content
• Higher ad fill rate generating more impressions – the average completion rate for SSAI ads on live is 98% – based on a real customer sample (June 2022)

CSAI benefits 💥

• Can support skippable, clickable and closable ads  
• Rich tracking and metrics for ad performance reporting  
• Can be deployed without ad markers  

Data rights and advertising ⚖️

Before you start serving personalised ads to viewers, you need their consent to use their data for this purpose. This is where you need to ensure you have a consent management platform (CMP) integrated with your applications and web services, as without it you aren’t compliant with data regulations. At Simplestream, we provide CMP integration in all our applications through Sourcepoint, to comply with GDPR, ePrivacy, and CCPA regulations.  

Your choice of ad server 🔌

It’s not as simple as plug-and-play when it comes to ad insertion, but it could be with the right tech partner. Once you’ve made your choice of ad delivery method, you’ll need an ad server to provide these ads when a request is made. Simplestream has existing relationships with several ad servers including Google Ad Manager, SpringServe, FreeWheel, and SuperAwesome.