Data science in advertising goes far beyond predicting clicks. Over the last 15 years the field has evolved from simple CTR models into complex systems that integrate pricing, optimization under constraints, reinforcement learning, experimentation, and more recently the application of large language models (LLMs). This article organizes that technical journey into a clear map: what problems were solved first, how different components connect, and which challenges remain. The goal is not to list papers but to provide a structured view that helps distinguish between trend and foundation, and to show where AdTech is heading.

When someone hears data science in advertising, they often think of models that predict CTR or CVR. And yes that was the starting point. But the reality is much broader. Digital advertising combines prediction, real-time auctions, budget control, creative optimization, experimentation, and now even multimodal models. Understanding this entire ecosystem is difficult because knowledge is fragmented across academic papers, practical implementations, and internal systems that evolve over time. This article aims to organize that map.

Research in digital advertising was particularly active between 2010 and 2015; many foundational papers were born during that period.
The problem today is not a lack of information, but the opposite:
For newcomers, distinguishing between mature technology, current trends, and hype is a real challenge.
Data science in advertising can be understood as an evolution in layers:
These are not isolated topics they are parts of the same system.
The first major wave focused on prediction

Although they may seem old, many of these models remain competitive because of:
This is where everything begins but it is not where everything ends.
Once we can estimate probabilities, the key question arises: how do we use those predictions to bid better?
This brings in topics such as:
Digital advertising is not only prediction; it’s real-time strategic competition.
Advertising systems operate under clear limits:

This led to:
Here data science stops being purely static and becomes a sequential decision problem.
When multiple advertisers compete simultaneously, the problem becomes strategic rather than only predictive. The environment turns dynamic: each campaign learns, adjusts, and responds to others’ decisions. This is where multi-agent reinforcement learning (MARL) becomes relevant — you can no longer just estimate probabilities; you must act while considering that the system is constantly changing.
Key aspects:
Beyond bidding, performance depends on creativity, rigorous experimentation, and adaptation to a new privacy ecosystem. Optimization is not only technical but also methodological. Without solid evaluation, no model matters.
Important threads:

Data science in advertising is not a collection of isolated techniques but an interconnected system that has evolved from simple predictive models to complex architectures of decision-making, control, and experimentation. Understanding this full map makes it possible to distinguish between fashion and foundation, between real innovation and unnecessary complexity. Beyond CTR, the real challenge lies in integrating prediction, strategy, and evaluation in a dynamic, competitive, and increasingly regulated environment.