The modern ad server has evolved significantly since the early days of digital advertising, and yet, has remained more essential today than ever before. Let’s take a look at some of the major changes that ad serving has been through in the last 24 years by examining the four eras of ad serving.

In the early days of ad serving around the mid-90's, the cookie and the IP address were two innovative features that allowed advertisers to measure the number of unique visitors, the frequency of their visits, and their locations. Once impression and click trackers arrived, advertisers could start the process of basic personalization.  

Advertisers were able to engage in more sophisticated creative executions as internet speed and bandwidth increased dramatically. Ads became more and more complex and widespread which often led to broken code and a bad user experience. This led to a need to implement precautions that could prevent this. Publisher certification was introduced to ensure compatibility between ads and websites. As publishers became certified, advertisers were given a guarantee through their ad server that their ads were being shown on legitimate websites with safe content.  

With more channels being added to the marketing mix, advertisers needed cookies to track which channels delivered the most impact. Cookies also brought granular data on users resulting in early forms of Dynamic Creative Optimization (DCO), with ads being able to display personalized messages based on data around an individual’s interests and behavior. At this time, smartphones began to flourish. In response, the industry started to create ads specifically designed for mobile browsers and apps.  

When video and TV content migrated online, the money quickly followed suit. Budgets for digital advertising grew substantially, which also led to more fraud and a need for further scrutiny from advertisers. This prompted ad servers to implement viewability measurement within the ad buying infrastructure.

Gradually, advertisers began to adopt bidding strategies in order to purchase inventory while the accuracy of targeting also improved. As opportunity increased, the use of unscrupulous ad serving led to widespread exploitation, aggressive ads, and malware. Users began demanding the ability to opt-out of ads and eventually downloaded ad blockers. The industry and legal authorities in Europe responded by introducing the General Data Protection Regulation (GDPR) and in the US with the California Consumer Privacy Act (CCPA). The legislation provided a framework to ensure that vendors were following the same rulebook and bad actors could be punished appropriately and removed from the ecosystem.  

Throughout this period, the technology for processing data became significantly more intelligent, with new analyzing and retargeting methods becoming available such as machine learning and look-a-like modeling. DMPs began to mature and the value proposition of an Integrated Advertising Platform emerged as the importance of real-time actionable data grew. 

The evolution of ad serving involved a series of innovations, both reactive and proactive, that worked to enhance the way advertisers interact with consumers. Throughout this evolution, the fundamental principles of marketing – such as, increasing share-of-voice and creating impactful branding – have remained the same. However, these fundamental principles are enhanced by a plethora of new tools and features that have led to greater reach, personalization, efficiency, and impact.