Marketing & Ad Fraud Glossary

What is display advertising?

Display advertising is a form of online advertising that uses visual creative — banner images, rich media, and video — placed on websites, apps, and platforms. It is typically bought programmatically through real-time auctions and priced on a CPM or CPC basis.

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How display advertising works

Unlike search ads, which respond to a user’s query, display ads are shown to users as they browse content — reading an article, using an app, watching a video. The goal is usually awareness, consideration, or retargeting rather than capturing immediate intent.

Most display inventory today is traded programmatically: advertisers use a demand-side platform (DSP) to bid on impressions in real time, publishers offer inventory through a supply-side platform (SSP), and the two meet in an ad exchange. This automation makes display advertising fast and scalable — but also harder to police.

Common display ad formats

Banner ads

Static or animated image units in standard IAB sizes.

Rich media

Interactive units with video, expansion, or in-ad functionality.

Interstitial ads

Full-screen units shown between content views, common in apps.

Video display

In-stream and out-stream video creative.

Native display

Units styled to match the look and feel of the host page.

Why display advertising attracts ad fraud

Because display inventory is bought programmatically from a long tail of third-party publishers, it is one of the most fraud-exposed channels in digital advertising. Fraudsters can hide large volumes of invalid traffic inside legitimate-looking supply.

The Opticks Ad Fraud Report 2025 measured a 15.43% invalid-traffic rate on programmatic — the channel that carries most display inventory — versus just 2.18% on search. Native display ran even higher, at 15.9%.

Common display ad fraud techniques

Ad stacking

Multiple ads layered in one placement; only the top one is visible, but all are billed.

Pixel stuffing

Ads crammed into 1×1-pixel frames that no human ever sees.

Domain spoofing

Low-quality inventory disguised as a premium publisher.

Bot impressions

Automated software loading ads to generate fake views and clicks.

How to protect display campaigns

Effective protection means scoring traffic in real time — at network, application, and user level — rather than relying on simple IP blocklists. Opticks detects more than 30 types of invalid traffic across display, programmatic, and every other channel, keeping budget on real people.

Source: Opticks Ad Fraud Report 2025 — 2 billion clicks analysed, data through Q1 2026.