CTV Inventory: A Guide for Advertisers and Brands

In the early days of streaming television, connected TV (CTV) stood apart from traditional linear TV not just for delivering shows and movies on demand, but for being ad-free. Users paid a monthly subscription fee, usually less than the cost of two lattes, and could watch endless hours of content without a single commercial interruption.

Since then, as streaming platforms sought to diversify their revenue and viewers searched for more affordable options, nearly every major service—Netflix, Disney+, Max and Prime Video included—has launched a lower-cost, ad-supported tier.

The result: ad-supported streaming has not only helped reduce cancellations and lower subscription costs for viewers (56% of new streaming service subscribers chose a lower-priced ad tier in Q1 2024, a 39% increase from the year prior), but it opened up new ways for advertisers to connect with audiences through premium CTV inventory.

With its growing audience (over 75% of US homes have at least one ad-supported subscription), CTV has become one of the fastest-growing channels in programmatic advertising. Nine streaming services are projected to generate over $1 billion USD in ad revenue by 2026, and CTV ad spending is on track to officially surpass traditional TV ad spend, reaching $46.89 billion USD in 2028.

If you’re new to CTV advertising, here’s everything you need to know about CTV inventory.

What Is CTV Inventory?

CTV inventory refers to the advertising spaces available through platforms and devices that stream online content, such as smart TVs, streaming devices, and gaming consoles. CTV inventory typically consists of 15 or 30-second ad slots that appear before, during, or after programming that advertisers bid on or purchase directly through programmatic deals or private marketplaces.

Types of CTV Inventory

CTV inventory is typically separated into two main categories: premium and non-premium.

• Premium CTV inventory is ad space generally associated with reputable publishers—think household names like Disney, Netflix, and Max—known for their high-quality content and prestige programming. 
• Non-premium CTV inventory generally refers to ad placements in streaming services that typically have a lower reach or may provide content for more niche audiences.

Because of its association with top-tier publishers, premium CTV inventory is synonymous with performance. But, depending on the goals of your campaign and who you want to reach, even lesser-known publishers and niche platforms can drive substantial engagement and results.

How to Buy CTV Inventory

There are two primary methods marketers use to purchase CTV inventory: programmatically and non-programmatically (also known as direct).

Direct vs. Programmatic

In a direct buy, advertisers purchase ad slots directly from publishers or streaming platforms through negotiated agreements or upfront deals. 

Although purchasing CTV inventory directly from publishers can provide access to premium inventory that may not be accessible through programmatic channels, it also usually requires a higher minimum spend and can reduce the scale of your campaign reach because publishers typically only provide inventory on their own streaming services.

Programmatic buying, on the other hand, automates the process, allowing advertisers to bid on or negotiate available ad space through open auctions, private marketplaces or programmatic guaranteed deals. This allows advertisers to streamline their media buying and expand their reach, acquiring ad space across multiple publishers—often from a single platform—while reducing overall costs.

CTV Inventory Sources and Providers

When it comes to buying CTV inventory, advertisers usually acquire it through three main sources:

1. Direct Deals with Publishers: Advertisers negotiate directly with streaming platforms or publishers like Netflix and Prime Video to secure ad space. This often involves upfront commitments.
2. Demand-Side Platforms (DSPs): Programmatic platforms like StackAdapt allow advertisers to purchase CTV inventory programmatically, providing access to multiple publishers and platforms through a single interface. For example, through StackAdapt, advertisers can bid on or negotiate CTV inventory—nationally and internationally—through Disney+, Bell Media, Channel 4, NBCUniversal, and more.
3. CTV Devices and Operating Systems: Companies like Roku and LG offer ad inventory through their proprietary platforms and operating systems. These ecosystems host apps for streaming services and serve their own ads, such as banner ads on home screens or ads within free content and channels.

CTV Inventory Formats

CTV inventory comes in various formats to suit your CTV advertising strategy or the goals of your campaign:

• Pre-roll ads play before a video plays.
• Mid-roll ads appear in the middle of or during content.
• Post-roll ads play at the end of content.
• Non-linear ads (or overlay ads) are displayed alongside or on top of content without pausing or interrupting it.
• Companion ads appear alongside the video player, typically on the same screen, providing additional messaging without disrupting the viewing experience.

As technology advances, CTV inventory continues to evolve, with adtech companies and CTV publishers experimenting with different formats—such as QR codes, split-screen ads, and shoppable ads—that can increase engagement, tie ad views to conversions, and shorten the customer journey.

How Much Does CTV Inventory Cost?

The cost of CTV inventory can vary greatly depending on the streaming service, target audience, and type of content involved. Premium CTV inventory often carries higher CPMs, while the number of ads shown per hour can also impact the pricing (for example, top-tier publishers with premium inventory—like prestige TV shows and movies—generally have less ad space available than a free ad-supported streaming channel, which often shows 9 minutes of ads per hour).

That said, CTV inventory is getting more accessible.

At the start of 2024, Prime Video’s ad-supported tier flooded the market with inventory, undercutting other streaming services and forcing them to lower their CPMs to stay competitive.

In doing so, it lowered the barrier to entry, especially for smaller and niche agencies and brands. By Q2 2025, EMARKETER predicts that Netflix will be one of only two streaming platforms with CPMs higher than $30 USD.

The Future of CTV Inventory

CTV is evolving. Despite predictions that linear TV and streaming TV could lose up to a quarter of their combined ad volume by 2027, opportunities for advertisers are increasing thanks to lower operational costs, shifting consumer behaviour, and new avenues like live sports advertising.

If you want to learn more about CTV advertising and how to prepare for the future, download StackAdapt’s Ultimate Guide to CTV Advertising or speak with our team.