YouTube is a key channel for advertisers, and is positioning itself as ‘TV’ rather than online video. In the US for example, it now accounts for nearly 14% of all TV viewing, more than any other individual media distributor – and that is a pattern being seen globally as well. It therefore makes sense that YouTube is an increasingly important feature on many media strategies. But as investment grows, so too does the range of content across which that investment can be spread. At what point does scale turn into loss of control?
In our recent media performance work, ECI has seen a striking increase in the number of YouTube channels on which advertisers' campaigns are running. Where campaigns might previously have appeared across hundreds of thousands of channels, we are now seeing cases involving more than three million. This raises an important question for advertisers around whether reaching millions of YouTube channels actually improves media performance, or if it simply increases exposure to low-quality inventory while making oversight increasingly difficult.
YouTube has an enormous range of content, from major broadcasters, established creators and specialist publishers to tiny channels with minimal audiences. It also includes material created primarily for children, low-quality automatically generated video, and a rapidly growing volume of AI-generated content. Not all of this material is necessarily unsafe, and appearing against it doesn’t necessarily mean that media investment has been wasted or brand safety has been compromised. However, there is a distinction – an important one –between content that meets a platform's minimum standards for monetization and inventory that an advertiser would actively choose as an appropriate environment for its brand.
The way YouTube inventory is bought has also become increasingly automated. Campaigns can now optimize across a broader range of formats and inventory, including Shorts, while Google's inventory settings are designed to give advertisers access to varying levels of content depending on what they need. This may be contributing to the rapid expansion in the number of channels included in campaigns, although the precise drivers will vary according to campaign set-up.
Our analysis has repeatedly identified spend across very large numbers of channels, many of which account for only a very small proportion of overall delivery and, in some cases, raise significant questions around media quality.
The rapid growth in the number of channels also creates a transparency challenge – the larger the placement list, the harder it becomes to extract, process and analyze channel-level data. At the extreme, advertisers can find themselves with campaigns spread across millions of placements but with a diminishing ability to understand exactly where their investment went.
Programmatic advertising on the open web has faced similar issues, and there is a useful comparison to draw. The ANA's Programmatic Media Supply Chain Transparency Study recommended that advertisers prioritize inclusion lists rather than exclusion lists, as attempting to identify and exclude undesirable sites from a constantly expanding number of them is a Sisyphean task. In the ANA study, the average campaign appeared across 44,000 websites, yet 86% of impressions were concentrated on just 3,000. The challenge becomes even more acute when campaigns run across millions of channels, as is the case on YouTube, making the principle of actively managed inclusion lists a practical option that gives advertisers greater control over where their investment appears.
We are also seeing a growing number of placements reported simply as ‘channel no longer available’. This can happen when a creator removes a channel or when YouTube removes it for violating platform policies. In either case, it leaves advertisers with limited visibility into the environment in which their ads originally appeared. When this is combined with an already extensive long tail of channels, it creates another potential source of risk and reinforces the case for a more actively managed inclusion approach.
For many advertisers, a manageable selection of established channels may provide sufficient audience scale while also meeting agreed standards for content quality, suitability and brand alignment. That would ideally mean hundreds or thousands of channels, rather than millions; the precise number matters less than whether the scale of the channel list is delivering a clear benefit in terms of reach, performance or efficiency.
There is, however, a trade-off. Restricting inventory may increase CPMs or reduce some of the efficiencies available from automated buying. Google itself advises advertisers that extensive suitability controls can limit reach and increase CPMs - its inventory and content suitability settings are designed to give advertisers different levels of access to YouTube inventory, depending on their requirements. However, the lowest possible CPM doesn’t always – indeed, often doesn’t – mean the highest possible media value. An impression delivered inexpensively is only valuable if the advertiser wanted that impression in the first place. Media quality, audience relevance, transparency and the environment in which the ad appears all form part of the value equation.
This is particularly important because some placement reporting is itself subject to limitations. Google notes that ad placements, including those on YouTube, are only reported when they meet certain minimum thresholds, while some campaign and inventory types don’t provide comprehensive placement-level reporting. As campaigns spread across ever larger numbers of channels, extremely large placement reports can become difficult to extract and analyze. This makes independent scrutiny increasingly difficult just as the inventory mix becomes more fragmented.
Advertisers need to understand the inventory strategy their agency is using for YouTube, rather than viewing it simply as a technical platform decision. They should also ensure that their agency’s approach reflects their own priorities around quality, cost, suitability and transparency.
Useful questions to open productive discussions with the agency could include:
• How many YouTube channels did our campaigns appear on during the reporting period?
• How has that number changed over time?
• What proportion of impressions and spend sits within the long tail of channels?
• What quality and suitability criteria determine where we appear?
• Are we primarily relying on exclusions, or have we considered a defined inclusion strategy?
• How frequently are channel lists and suitability controls reviewed?
• What incremental reach or performance do we gain from expanding beyond our core channel list?
• Can we obtain sufficiently granular placement data to independently assess the quality of that inventory?
A campaign appearing across millions of channels is not inherently evidence of poor buying - but neither should such scale be accepted without scrutiny. As the sheer scale of content on YouTube continues to expand, advertisers may need to rethink the assumption that being able to access more inventory is automatically better. A smaller, actively managed list may cost slightly more, but when it delivers greater quality, transparency and control without sacrificing effective reach, that could be money well spent. Ultimately, the objective should always be to identify the inventory that delivers the highest media value, not just to access as much inventory as possible.