IAB Europe’s AI Prompting Guide

Artificial intelligence is rapidly reshaping how digital advertising is planned, created, and optimised. From creative generation to data analysis and workflow automation, AI is becoming embedded across the advertising supply chain. But unlocking its real value depends on one critical skill: prompting.

Developed by IAB Europe’s AI in Advertising Working Group, this AI Prompting Guide demystifies the art and science of prompting, showing you how to communicate more effectively with AI models to produce reliable, high-quality outputs. Whether you are experimenting with chat-based tools or building advanced AI-powered systems, this guidance helps you work smarter, faster, and more responsibly with AI.

What’s Inside the Guide

The guide provides practical, reusable techniques you can apply immediately, including:

• How to write clearer, more effective prompts
• Balancing positive and negative instructions
• Using system prompts to control tone, role, and behaviour
• Iterating and refining outputs efficiently
• Applying prompt templates and structured formats like JSON
• Understanding key parameters such as temperature, context windows, and output limits
• Managing risks such as hallucinations, bias, and prompt injection

It also includes a shared set of definitions to build common understanding across technical and non-technical teams.

A huge thank you to the following contributors for helping with this guide:

• Google
• Microsoft
• Pubmatic
• MarkApp
• ShowHeroes
• BVDW
• IAB Finland
• SPIR
• IAB Austria