Articles
Understanding SSP, DSP & Ad Exchanges
In this blog post, we take a closer look at both systems, explain their individual roles, and show how they work together with Ad Exchanges to enable the delivery of digital advertising.
June 2025
Imagine this …
… you run a popular website. Tens of thousands of people visit your site every day. You want to monetize this traffic – but without introducing a paywall.
The solution: digital ad space on your website. Instead of laboriously acquiring advertisers yourself, you rely on automation – and integrate what’s known as a Supply-Side Platform (SSP).
What does an SSP do?
The SSP is your digital sales partner: it helps you, as a publisher, market your ad inventory efficiently. This process is fully automated – known asprogrammatic advertising. Today, a large share of digital ad budgets is managed this way. You can find out how much in our blog post on display advertising.
Modern SSPs increasingly rely on header bidding instead of the classic waterfall model. In the waterfall approach, ad inventory is offered to several partners one after the other – only if the first declines, the next is approached. This can result in potentially higher bids being missed. With header bidding, however, ad space is offered to multiple bidders at the same time – which typically leads to higher revenue for publishers.
As soon as someone visits your site, the SSP detects available ad slots and creates a request that includes targeting data (e.g. device type, location, user behavior). This request is forwarded in real time to potential buyers – among others via so-called ad exchanges.
The integration of first-party data is becoming increasingly important. Some SSPs offer proprietary solutions for this, such as the VIS.X® Identity Solution from YOC, which enables privacy-compliant audience targeting.
In the EU, the role of Consent Management Platforms (CMPs) is also key: only when users have given their consent may their information be used for targeting – an essential part of SSP-DSP communication.
What is an Ad Exchange?
An Ad Exchange is a digital marketplace. It’s where supply (your ad inventory via the SSP) meets demand (bids via DSPs). The Ad Exchange organizes the auction, forwards the bids, and awards the impression – all in a matter of milliseconds. Without this marketplace, SSPs and DSPs couldn’t communicate.
And what is a DSP?
On the other side are companies that want to purchase ad space efficiently, in a targeted and scalable way. To do so, they use a Demand-Side Platform (DSP). Within the DSP, they define who they want to reach, when, where, and at what price. The DSP is the technical solution on the demand side – it manages campaign booking and delivery.
Using audience characteristics, the DSP identifies suitable ad placements. Complex algorithms evaluate a wide range of data (e.g. website activity, third-party data) to automatically select the most relevant users.
One major advantage of DSPs is centralized control: advertisers don’t need to book with individual publishers – instead, they gain access to a broad inventory via a single platform. The decision as to which ad is served when is made in real time – based on data.
DSPs can be used independently or managed by a service provider – the latter often offers additional support in targeting, selecting suitable placements, and analyzing campaign results.
How do these three platforms work together?
All bids submitted via DSPs are collected through the Ad Exchange and sent back to the SSP, which organizes the real-time auction. Within milliseconds, the highest bid is selected. Before your site’s content has even fully loaded, the winning ad is already displayed. Here’s how it works – step by step:
DSP – The advertiser’s side
Campaign setup: Advertisers upload creatives, define target groups, targeting parameters and budgets.
Data integration: The DSP uses data to address audiences more precisely.
Marketplace integration: The DSP is connected to multiple SSPs and Ad Exchanges.
Real-time bidding (RTB): The DSP evaluates each request and submits a bid if there’s a match.
Auction & delivery: The highest bid wins and the ad is served immediately.
Monitoring: The DSP provides performance insights to optimize the campaign.
SSP – The publisher’s side
- Integration & inventory management: Publishers connect their website or app to the SSP.
- Ad request: Upon a page visit, the SSP sends a request with ad slot information.
- Forwarding to DSPs: The request is passed on to connected DSPs and Exchanges
- Real-time auction (RTB): Bids are evaluated and the highest one wins.
- Ad delivery: The winning ad is displayed immediately.
- Reporting: The SSP provides reporting for optimization.
What matters when choosing an SSP?
As the operator of a website, you want an SSP that markets your inventory efficiently, performs reliably, and suits your environment. Here’s what to look for:
• Reach & demand: The more DSPs and exchanges are connected, the higher your potential revenue.
• Access to premium campaigns: Brand advertising tends to be more trusted – and better paid.
• Innovative formats: Platforms like VIS.X® from YOC focus on high-impact formats, which – according to a study by Lumen – generate significantly more attention and advertising impact than standard banners.
• Transparency & control: Clear reporting helps you understand what’s being delivered.
• Brand safety & filtering: You control which ads and content are shown on your site.
• Technical support: Reliability and responsive assistance are essential.
Now you have a clear overview of how SSPs, DSPs and Ad Exchanges interact – and why the right setup is a key foundation for efficiently monetizing your website.
Want to go further?
