Buying and managing ad space manually is slow, costly, and inefficient. Ad servers have changed the game, using automation to deliver the right ads to the right audience in seconds. No wasted time, no missed opportunities.
In 2025, media owners’ ad revenue is expected to hit $1.1 trillion, up 7.7% from 2024. It’s projected to reach nearly $1.4 trillion by 2029. So now it’s clear this technology is essential. Ready to see how it works and what makes it so powerful? Let’s explore the ad server technology and programmatic advertising in detail.
What Is Programmatic Advertising?
Before diving into ad servers, it’s important to understand programmatic advertising. Programmatic advertising is an automated way of buying and selling ads online. Instead of manually negotiating ad placements, advertisers use ad tech platforms to bid on ad space in real time. This process, known as real-time bidding (RTB), happens in milliseconds while a webpage or app is loading.
With programmatic advertising, brands can target their ideal audience based on demographics, interests, and online behavior. It ensures ads are shown to the right people at the right time, making ad campaigns more efficient and cost-effective for programmatic monetization. This approach powers most digital advertising today, from banner ads and video ads to CTV and digital billboards.
Ad Server Basics
What is an ad server? Imagine you’re promoting fitness gear to potential customers. You want your ads to show up on their favourite sites and apps, quickly and seamlessly. That’s the job of advertising servers.
An ad server is a tool that manages, optimizes and delivers ads on websites or apps. It connects your ads with the right audience in real-time. With top ad servers, marketers can upload ads, set targets, and track campaign results. Modern ad servers also offer some advanced capabilities like real-time bidding (RTB), AI optimization, and detailed audience segmentation. They support omnichannel advertising across CTV, DOOH, mobile, and web, ensuring ads reach the right users efficiently.
Ad Server Technology as a Key Market Player
Ad server technology is essential in digital advertising, acting as the system that delivers, manages, and tracks ads across websites, apps, and other platforms. It allows publishers and advertisers to show the right ads to the right people at the right time.
Today’s ad servers go beyond just serving ads—they use AI to optimize performance, segment audiences, and manage ads across multiple channels like mobile, web, and connected TV. As the industry grows, ad servers are also helping address new challenges, like reducing the environmental impact of digital ads. For example, Scope3 offers a new business model in the industry. It measures carbon emissions and provides insights to advertisers, publishers, and ad tech companies on how to lower their environmental impact.
More about digital advertising trends in our recent blog post!
How Ad Servers Work: Behind the Scenes
As it implies from the ad server definition, ad server software processes ad requests, handles bids in real-time, and delivers ad responses based on targeting criteria, optimizing ad placements. Also, it collects statistics and provides reports to track the effectiveness of advertising campaigns.
Ad servers most often work together with demand-side platforms (DSP) and supply-side platforms (SSP), as well as advertising networks (Ad Network) and advertising exchanges (Ad Exchange). In this case, ad servers are a tool for delivering and placing ads on target ad spaces.
Publisher and Advertiser Ad Server
There are two main types of ad servers:
- A Publisher Ad Server is used by websites and apps to manage the ads they show. Think of it as a smart traffic controller that decides which ad appears, based on things like user data, advertiser bids, and available space. It also tracks how well ads perform—counting views, clicks, and revenue—so publishers can make the most money from their ad space.
- An Advertiser Ad Server, on the other hand, is what advertisers and agencies use to run their ad campaigns across different websites. It helps them control where their ads appear, how often they show up, and whether people are actually clicking on them. This server also tracks important stats like impressions, clicks, and conversions, so advertisers can see what’s working and tweak their ads for better results.
These two ad servers constantly talk to each other in real-time, making sure the right ads reach the right people at the right time.
First-Party vs. Third-Party Ad Servers
As you see from the scheme above, ad server software comes in two main types – first-party and third-party.
What is a First-Party Ad Server?
First-party ad serving is mostly used by publishers—organizations or individuals that own websites or apps on which ads are served. The servers thus allow them to control their advertising inventory on their own: deciding which ad to show, where, and when.
Main features of first-party ad servers:
- Publishers have full control over ad placement, making it easier to manage their inventory and for ads to align with their content.
- They monitor performance, such as impressions and clicks for the ads served across the publisher’s properties, giving an insight into ad effectiveness.
- First-party ad servers are mainly used to manage those ads sold directly to the advertisers, helping the publishers maintain full control over their inventory.
What is a Third-Party Ad Server?
Third-party ad servers are built for advertisers and ad agencies that manage campaigns running across multiple platforms. Advertisers or ad agencies use these servers to upload ad creatives and manage campaigns.
Main features of third-party advertising servers:
- Advertisers can manage campaigns on several publishers through a single platform.
- The metrics utilized are standardized across various placements, thereby facilitating the assessment of campaign performance.
- Ad verification tools ensure that ads are delivered properly, track viewability, and offer protection against fraud or misplacement.
Key Differences
Key Features of Programmatic Ad Servers
Generally, ad servers improve advertising workflows, create better advertising experiences for publishers and audiences, and maximize ROI. For example, programmatic advertising makes up more than 80% of all display ad purchases in the US.
If we look deeper, the functionality of ad servers makes programmatic advertising:
- Real-time trading: Ad purchases are made in fractions of a second.
- Targeted: Ads are selected for specific audiences based on user data.
- Efficient: Reduces time and resources compared to traditional methods.
Moreover, the ad server easily integrates with SSP, DSP, Ad Networks, and Ad Exchanges.
Other Types of Ad Servers
- Display ads
Display ad servers are designed to manage and deliver banner ads, rich media, and other visual ad formats across websites and apps. These ad servers handle the placement of static or interactive ads, ensuring they reach the right audience based on targeting criteria like demographics or behavior. Display ad servers also track key metrics like impressions, clicks, and conversions.
- Video ads
Video ad servers focus on delivering video content across platforms like websites, apps, and streaming services. These ad servers handle everything from pre-roll and mid-roll ads to in-stream and out-stream video ads. They help advertisers track video engagement, like views and completions, and optimize performance based on audience interaction.
- Digital Out-of-Home (DOOH)
Digital out-of-home advertising is increasingly moving toward programmatic. Ad servers for DOOH manage digital billboards, screens, and other outdoor media. By using programmatic buying, DOOH ad servers can deliver targeted, real-time ads based on location, audience, and time of day, making outdoor advertising more dynamic and data-driven.
- Digital audio
Digital audio advertising, which includes ads on streaming platforms, podcasts, and music services, is also becoming more programmatic. Audio ad servers help advertisers deliver targeted audio ads based on listener preferences, demographics, and listening behavior, ensuring ads reach the right audience at the right moment, just like other digital ad formats.
IAB (The Interactive Advertising Bureau) Europe is regularly compiling and updating a collection of the current guidelines for the different digital advertising formats and channels.
Real-World Examples of Ad Servers
Ad servers are the engines that make the digital advertising ecosystem work. Depending on your business goals and needs, ad servers will use the same functionality in different ways to help you manage the scope of your digital marketing efforts.
Google Ad Manager – This tool helps publishers manage and deliver ads across their websites and apps. It combines the features of Google AdSense and Google Ad Exchange, making it easy to serve display, video, and rich media ads.
With Ad Manager, you can target specific audiences, track how well your ads are doing in real-time, and automate parts of the ad process. It also allows you to manage both direct sales and programmatic ads in one place, helping you maximize revenue. It’s a go-to platform for advertisers looking to reach people across Google’s vast network.
Amazon Ad Server – It is a good example of an ad server. As a third-party, multi-channel platform, it helps advertisers and agencies create, manage, and optimize digital campaigns. Amazon Ad Server allows ad creators to easily export and generate assets such as banners or videos and offers the flexibility to seamlessly move creatives between different ad servers for a seamless experience.
Revive Adserver is a free open-source advertising server that is licensed under the GNU General Public License. It features an integrated banner management interface and tracking system for gathering statistics. It used to be known under different names in the past, most recently as OpenX Source.
SSP vs. Ad Server: Are They the Same?
Both SSP and ad servers are critical in the digital ad ecosystem but they have different roles. SSPs are focused on selling ad space, and ad servers are focused on serving and tracking ads. They work together but have distinct roles in programmatic advertising.
Key Differences
- Main goal: An SSP helps publishers sell their ad inventory. An ad server delivers and tracks ads.
- User: SSPs are mainly used by publishers to optimize ad revenue. Ad servers are used by both advertisers and publishers to manage and track campaigns.
- Focus: SSPs optimize the sales side and help publishers to better monetize their advertising space. Ad servers focus on delivering and tracking ads.
Some ad servers combine different functions in them. For example, Adtelligent Ad Server has a full-stack infrastructure—including SSP, DSP, and oRTB. It is designed to help publishers fully optimize programmatic revenue and provide a transparent mechanism for yield optimization. Key features:
✅ AI-powered optimization – Adtelligent analyzes real-time and historical data to maximize ad performance.
✅ White-label solution – Fully customizable API-based platform.
✅ Fraud prevention – Scoring-as-a-service detects malware and eliminates fraudulent traffic.
✅ Programmatic bidder – Custom oRTB bidder for seamless trading.
✅ Adtelligent marketplace – Buy and sell media efficiently.
✅ Omnichannel & Cross-device – Designed for maximum reach and engagement.
How to Track Ad Server Performance
Generally, the effectiveness of programmatic advertising and publisher ad servers is measured by KPIs such as click-through rate (CTR), conversion rate, return on ad spend (ROAS), and cost per acquisition (CPA).
Other important metrics to track include visibility, which measures how often ads are seen by users, reach, which tracks the number of unique users exposed to your ads, and target group engagement, which measures how well your ads resonate with the intended audience. These metrics help assess the efficiency of your campaigns and the overall reach of your ads, ensuring you’re getting the most value from your ad server technology.
How to Decide Which Ad Server is Right for You
The choice of an ad server largely depends on your role and current business objectives. To make the right decision, it is important to understand how much time and effort you can invest in implementing a solution that best suits your goals.
- For publishers, the key factor will be support for various ad formats, the ability to independently manage accounts for advertisers, and the availability of tools that help highlight ads with a high CPM (cost per mille).
- For advertisers, it is important to pay attention to conversion measurement functions, A/B testing capabilities, high-quality analytics, and access to APIs for process customization.
- Ad networks usually look for solutions with white-label functions, flexible permission settings, and support for a wide range of ad formats.
Assess your needs and choose a tool that will provide optimal support for your business processes.
Key Takeaways
Ad servers are the backbone of online advertising. They power the delivery of ads across websites, social media, and mobile apps. To truly optimize and manage your campaigns, a reliable ad server can unlock greater revenue through advanced tools. Let’s help you turn every ad request into an opportunity to grow.
FAQ
What is the difference between an Ad Server and a DSP?
Ad servers focus on delivering and tracking ads across websites and apps, while DSPs help advertisers purchase ad space across various publishers programmatically. DSPs use RTB to bid for the best ad placements.
Where do I find publishers for my ad campaigns in Ad Servers and DSPs?
In an Ad Server, publishers are usually integrated, and you work with them directly. In a DSP, you access publishers through ad exchanges or supply-side platforms (SSPs) that offer ad space for bidding.
Is it possible to white-label these platforms?
Yes, some ad servers and DSPs offer white-label solutions, letting you customize and brand the platform for your business or clients.
Building vs. Buying Ad Server
Building your own ad server allows for full customization but requires significant resources, expertise, and maintenance. Buying an existing ad server offers quicker implementation and reliability, with support and updates from the provider. The choice depends on your business needs and available resources.
What is an Ad Exchange?
An ad exchange is an online marketplace where advertisers bid for ad inventory from multiple publishers using RTB. It offers transparency and competition, allowing advertisers to see where their ads will appear.
Is Google Ads a DSP?
Yes, Google Ads is a DSP, but it’s limited to Google’s inventory. Third-party DSPs offer access to additional inventory outside of Google’s network, expanding targeting options.
What is Header Bidding?
Header bidding lets publishers request bids from multiple demand sources at the same time, increasing competition and allowing advertisers to access premium inventory.
How are Programmatic Ads Bought and Sold?
Programmatic ads are bought and sold automatically using DSPs and SSPs. Advertisers bid on inventory in real-time, and the highest bid wins, allowing ads to be shown to the right audience across multiple platforms.
This process is complex and fragmented, but it’s growing fast, with a 5.7% YoY increase in programmatic ad sales. To ensure efficiency, building a programmatic ad tech stack requires 100% uptime, as real-time bidding (RTB) plays a crucial role in auctioning ad space to the highest bidder. DSPs help advertisers buy ad inventory across multiple publishers.
What is Real-Time Bidding (RTB)?
Real-Time Bidding (RTB) is the process of auctioning ad space to the highest bidder in real-time. It allows advertisers to target specific users and get the most relevant ad placements based on audience data.