What is a companion banner on CTV?

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Last updated: April 8, 2026

Quick Answer: A companion banner on CTV (Connected TV) is a secondary digital ad unit that appears alongside the main video ad during streaming content, typically displaying text, images, or interactive elements. It enhances viewer engagement by providing additional information, calls-to-action, or brand reinforcement without interrupting the primary video. For example, a 2023 IAB study found that companion banners can increase brand recall by up to 40% compared to standalone video ads. These banners are commonly used in CTV advertising to drive metrics like website visits or app downloads, with platforms like Roku and Amazon Fire TV supporting them since around 2018.

Key Facts

Companion banners on CTV are secondary ad units displayed alongside main video ads during streaming
They can increase brand recall by up to 40% according to a 2023 IAB study
Commonly used to drive actions like website visits or app downloads without interrupting video
Supported by major CTV platforms like Roku and Amazon Fire TV since approximately 2018
Typically include text, images, or interactive elements for enhanced engagement

Overview

A companion banner on CTV is a digital advertising feature that originated in the late 2010s as streaming services and connected TV devices gained popularity. With the rise of CTV advertising, which grew from $8.1 billion in 2020 to over $25 billion in 2023 according to eMarketer, advertisers sought ways to enhance engagement beyond traditional video ads. Companion banners evolved from web display ads, adapted for the CTV environment where viewers use remote controls instead of mice. They first appeared around 2017-2018 on platforms like Roku and have since become standard in CTV ad campaigns, particularly for brands aiming to drive specific actions like product awareness or conversions. The technology leverages the interactive capabilities of modern CTV devices, which reached over 200 million U.S. households by 2023.

How It Works

Companion banners on CTV function by integrating with the CTV advertising ecosystem through several technical steps. First, when a user streams content on a CTV device (like a smart TV or streaming stick), the platform serves a video ad from an ad server. Simultaneously, a companion banner is triggered to appear in a designated area of the screen, often at the bottom or side, using HTML5 or similar web technologies for rendering. These banners are typically delivered via programmatic advertising systems, such as those using VAST (Video Ad Serving Template) 4.0 or later standards, which support companion ad slots. The banner content—which might include text, logos, or interactive buttons—is synchronized with the video ad to reinforce the message. For example, during a car commercial, a companion banner could show a "Learn More" button that viewers can select with their remote to visit a website. The process involves real-time bidding and targeting based on viewer data, ensuring relevance without disrupting the viewing experience.

Why It Matters

Companion banners on CTV matter because they significantly impact advertising effectiveness and viewer experience in the growing streaming market. They provide a non-intrusive way for brands to boost engagement, with studies showing they can lift click-through rates by 15-20% compared to video-only ads. In real-world applications, companies like Nike or Coca-Cola use them during sports streams to drive app downloads or promotional offers, enhancing ROI. Their importance lies in bridging the gap between passive viewing and interactive marketing, especially as CTV ad spend is projected to exceed $30 billion by 2025. By offering additional touchpoints, companion banners help advertisers combat ad-skipping and improve metrics like brand lift, making them a key tool in modern digital advertising strategies.