The endless game of cat and mouse: YouTube's escalating fued with ad blockers

The online video streaming wars have been raging for over a decade, with content creators, platforms, advertisers, and viewers all vying for control and their piece of the multibillion-dollar pie. At the heart of this conflict is a game of cat and mouse between YouTube and ad blocker developers, two forces locked in an escalating arms race to gain the upper hand. YouTube’s latest salvo, revealed in June 2024, appears to be a direct strike against ad blockers, threatening to checkmate them once and for all. But to truly understand the stakes, we must look back at how this epic battle began.

In the early 2000s, online video advertising was still in its infancy, with YouTube launching in 2005. As the platform’s popularity exploded over the next few years, advertising became more prolific. By 2010, YouTube had shifted gears, introducing increasingly frequent pre-roll video ads that users could not skip. This advertising deluge awoke a sleeping giant: the ad blocker community. Software developers struck back, creating browser extensions like AdBlock Plus designed to filter out promotions and restore an uninterrupted viewing experience.

On Android phones, YouTube Vanced, released in 2017, became one of the most popular third-party clients for YouTube. The app allowed users to experience all Premium features, and then some, for free. The biggest advantage of Vanced was the ad-free viewing. Data from Tinuiti’s 2023 ad-blocking study revealed that nearly one-third (31%) of adults in the United States utilize ad blockers. Thus it was clear that the ad revenue that YouTube had been counting on was under threat.

Not ones to go down without a swing, YouTube’s developers rolled up their sleeves and went to work in 2013. Forget blocking small third-party clients, YouTube even snuffed out Microsoft’s special YouTube app that they developed for Windows Phone. Their first counterattack was to update the platform’s code regularly, effectively breaking existing ad blockers until their creators adapted to new filtering rules. In 2013, TechCrunch reported that Google was paying AdBlock Plus to make them whitelist ads for the platform. This agreement with Google and other sites came to be known as the Acceptable Ads Program that was introduced by ABP. This partnership would allow only acceptable ads to be shown on websites, even if users had ad blockers installed. The program aimed to strike a balance between user satisfaction and revenue generation for websites.

But of course, that wasn’t Google’s long-term plan. In 2013 itself, Google banned all ad blockers from the Play Store, stating that excessive ads on a website would anyway decrease the website’s ranking on search engine results pages (SERPs). This kicked off a frenetic cycle of warfare, with each side rushing to deploy new countermeasures in response to the other’s latest moves. Ad blocker filter lists swelled in size, while YouTube’s code grew increasingly dense and inscrutable, all in an effort to obfuscate and re-obfuscate the ad delivery mechanisms.

In 2016, Google appeared to reverse its earlier decision to ban ad blockers from the Google Play store, a move which had seen the company pulling apps like Adblock Fast and stalling the updates for others, like Crystal’s ad blocker. Following an appeal from Rocketship, the developers behind Adblock Fast, Google re-approved and republished its app to the Google Play Store. The decision represented a change in course for Google regarding its position on what sort of apps the company would allow in its app store for Android devices.

From a source with knowledge of the situation, TechCrunch learned at the time of the original decision that Google had planned to only support mobile browsers that could block ads, including those with built-in ad-blocking features like the Adblock Plus browser, as well as those that supported ad blocking via extensions, such as Firefox, Javelin, and Dolphin browsers. However, Google decided that standalone ad blocking apps distributed via APKs, like Crystal and Adblock Fast, would not be permitted under its new guidelines.

Those apps and others had emerged following Samsung’s introduction of ad blocking support within its own mobile web browser in early February. The feature worked a lot like how Apple’s Safari supports ad blocking. Third-party developers could take advantage of Samsung’s new Content Blocker API, which allows them to build apps that work within the browser to block ads and other unwanted content that can slow down web pages, like trackers.

There was already some indication that Google may have been debating its decision ahead of Adblock Fast’s reinstatement, as Google’s policy was being inconsistently applied. While Adblock Fast was pulled, Crystal was merely slowed down; Google blocked its app update from going through, citing the same “violation” of its Android Developer Distribution Agreement as the reason.

TechCrunch reported that Google would now allow those apps that integrate with one another app through authorized channels, like APIs, but will continue to prohibit apps on Google Play that interfere with the functionality of other apps in an unauthorized manner. Rocketship, for example, received an email noting that Google had accepted its appeal, then the app was republished. As Google flip-flopped on its decision, other ad blocker makers remained more or less untouched by the shifting policy. For instance, Adblock Plus, which released a version of its ad blocker for Samsung Browser, never heard from Google nor had its app pulled. Crystal also remained online, with its developer, Dean Murphy, having his updates accepted by Google.

As the conflict intensified from 2016, YouTube began exploring new fronts. In April 2022, they cracked down on third-party YouTube apps like YouTube Vanced, popular alternatives for mobile users seeking to circumvent restrictions. The platform even went as far as to basically threaten users to abide by their guidelines by claiming that their accounts could be banned, after a policy change.

YouTube may terminate your access, or your Google account’s access to all or part of the Service if YouTube believes, in its sole discretion, that provision of the Service to you is no longer commercially viable.

Not to be outdone, ad blocker developers doubled down on their efforts. Machine learning algorithms were trained to identify and filter advertisements automatically, no matter how YouTube attempted to hide them. But in April 2024, YouTube was once again armed and ready to put third-party apps out of business. Apps like ReVanced which ended up taking YouTube Vanced’s spot, were rendered almost unusable after users started seeing errors when trying to stream content.

The latest skirmish? YouTube’s experiment with server-side ad injection in 2024, first reported by the developer of the SponsorBlock extension.

For years, YouTube had served advertisements separately from its core video content, with this separation allowing ad blockers to surgically remove promotions before they ever reached the viewer’s screen. But in June 2024, YouTube confirmed it was testing a radically different approach: server-side ad injection. With this method, advertisements are seamlessly stitched into the video stream itself before transmission, rendering them indistinguishable from the main content.

The implications of this shift are dire for ad blocker developers. By obfuscating the boundary between video and advertisement, YouTube has effectively neutralized any client-side filtering techniques. However, in a GitHub FAQ, shared within the same SponsorBlock thread, developers have made it clear that they aren’t backing down. Here’s what’s happening with the server-side ad injection:

YouTube’s server-side ad injection experiment does not require live re-encoding of content. Instead, it uses a playlist of video chunks, allowing ads to be swapped or concatenated into the stream. While this might make it challenging for ad blockers to filter out specific chunks, they can still function if they identify which chunks to ignore. Although this approach complicates the functionality of tools like SponsorBlock, it isn’t necessarily their end. SponsorBlock can still operate if YouTube displays UI elements indicating ad durations, which can be found through data analysis.

The impact on general ad blockers and third-party clients like yt-dlp and NewPipe remains uncertain but is expected to be minimal in the short term. Ad blockers, particularly those like uBlock Origin on Firefox-based browsers, will continue to be effective, though with increased difficulty. For third-party clients, the immediate concern is the new sign-in requirement to watch videos, rather than the ad injection itself. Additionally, tools like DeArrow may face challenges with offsetting issues affecting thumbnail submissions, but these should be manageable in ways similar to SponsorBlock’s adaptations.

For now, I set up the server to detect when someone is submitting from a browser with this happening and rejecting the submission to prevent the database from getting filled with incorrect submissions.

When contacted by Bleeping Computer for a word on their plans for ad injection, a YouTube spokesperson said the following:

YouTube is improving its performance and reliability in serving both organic and ad video content.

This update may result in suboptimal viewing experiences for viewers with ad blockers installed.

Ad blockers violate YouTube’s Terms of Service, and we’ve been urging viewers for some time to support their favorite creators and allow ads on YouTube or try YouTube Premium for an ad-free experience. – Google spokesperson

As this epic battle rages on into its second decade, one thing is clear: the stakes have never been higher. For YouTube and its advertisers, maintaining a robust ad revenue stream is an existential imperative, one that ensures the platform’s continued growth and dominance. Failure is quite simply not an option in the cut-throat streaming wars.

Ad blocker developers, on the other hand, are fighting to preserve a fundamental ideal: the right of users to curate their own online experiences, free from the endless barrage of corporate promotions. Their mission is as much philosophical as it is technical, a digital extension of the age-old struggle between consumer choice and corporate interests.

In the end, this conflict may come down to an ideological schism as much as a technological one. Do we prioritize the commercial prerogatives of multi-billion dollar companies? Or do we uphold the autonomy and privacy of users in an increasingly monetized internet? The biggest part of the problem is YouTube’s disastrously bad implementation of ads, as documented by PiunikaWeb. The current state of YouTube ads makes the viewing experience almost unbearable. If you have a YouTube Premium subscription, try turning on Incognito mode in the app to experience what the average viewer has to deal with.

For now, the game continues its frenetic pace. YouTube has made its big move in 2024, unleashing server-side ad injection in a bid to seal its long-sought checkmate victory over ad blockers. Whether this gambit proves successful, or merely provokes a new wave of counter-moves from the remarkably resilient ad blocker resistance, remains to be seen.

But one thing is certain: the war over online video advertising is only intensifying after raging for over 15 years. And the ultimate outcome will shape the digital landscape for content, privacy, and corporate interests for decades to come. The battle lines have been drawn; which side will emerge victorious is anyone’s guess, at the moment.