Understanding EasyList: The backbone of ad blocking

The internet has become an indispensable part of our daily lives, but intrusive ads often disrupt our online experience. To combat this, ad-blocking technology has emerged as a powerful tool for users seeking a cleaner and more efficient online experience. But while users seek a less intrusive, clutter-free online environment, there’s a fundamental component at work that many are not aware of: filter lists.

Filter lists are the backbone of ad blocking. Essentially a set of rules used by ad blockers to determine which content should be blocked on web pages, filter lists provide the “insight” or “intelligence” that enables ad blockers to identify regular content vs advertisements. Think of it this way: when you browse the internet with an ad blocker enabled, the ad-blocking software consults these filter lists to decide what to allow and what to block. Without these lists, ad blockers would struggle to effectively identify and block ads across the vast landscape of the internet, ultimately helping users get the ad-light experience they’re looking for.

At the heart of this functionality is EasyList, one of the most widely used ad-blocking filter lists. 

EasyList is an open-source, community-run list of rules. EasyList plays a pivotal role in shaping how ads are displayed and blocked across the internet, impacting not only users but also publishers and advertisers. By understanding EasyList's role and its implications, we can better navigate the complex dynamics between user experience, advertising revenue, and the future of online content.

EasyList is a community-driven project maintained by volunteers who work to create and update filter lists that block intrusive ads. The project's primary goal is to enhance user experience by eliminating all ads and supporting a cleaner, faster web browsing experience. Open to the public, anyone on the web can locate EasyList and its filter lists. All users can use EasyList’s public forum to highlight websites with intrusive content, typically ads, for potential blocking by Filter List Authors. 

How does EasyList work?

A group of volunteer Filter List Authors frequently update the list of rules used by most ad block extensions and browsers to block ads. These authors believe in and focus on a better online user experience for the masses.  They use the forum as a way to facilitate ad block requests.

For instance, if a request complies with their policy, the Filter List Authors will add the flagged website or ad source to EasyList or the most appropriate filter list. These rules detect and remove ads based on specific patterns, including URLs, scripts, and page elements. For more information on EasyList’s policy on what gets blocked, click here.

EasyList and ad blockers

How does EasyList work with ad blockers? 

Most common ad blockers, such as uBlock Origin, AdBlock*, Adblock Plus*, Brave and Opera, use EasyList as their default blocklist to help identify and remove ads from websites. For example, when a user visits a website with banner ads and pop-ups, EasyList rules prevent them from appearing in the user's browser.

*see the advanced settings in AdBlock/Adblock Plus

But while EasyList enhances the user experience for millions of online users by blocking intrusive ads, it also affects the business models of publishers and retailers who rely on advertising. This creates new challenges for them in reaching audiences and maintaining revenue streams.

Challenges faced by retailers and publishers

Loss of ad revenue from blocked ads and reduced visibility for sponsored content (another type of advertisement) are some of the many significant challenges faced by retailers and publishers due to EasyList. EasyList's success in blocking ads comes with a trade-off: it may improve the online experience but creates obstacles for businesses that depend on ad revenue.

Publishers and retailers can request adjustments to EasyList rules. However, if the content is an advertisement, EasyList will not unblock it. Only false positives (e.g. content that is incorrectly blocked caused by filters that are too broad) can be unblocked. 

What ads does EasyList block?

Here lies the main challenge for most retailers and publishers – the types of ad formats it blocks. EasyList blocks display ads such as banners, pop-ups, and auto-playing video ads, as well as other ad types outlined in its policy. EasyList also maintains a separate list called EasyPrivacy to block tracking scripts that collect user data.

And as for sponsored product ads – they are also blocked by EasyList due to misuse in the past. Once upon a time, self-promotional ads on the primary website were allowed according to EasyList, i.e. if a publisher/retailer were advertising their own products. But some retailers found a loophole and started using sponsored ads to promote third-party advertiser products, particularly ads that were irrelevant to user search queries and/or were showing overpriced products. Furthermore, retailers also created a lot of buzz around "retail media networks" as a way to run ads on their websites and monetize user data by selling it as ‘audience extensions’. This caught the attention of Filter List Authors, like those behind EasyList, who responded by blocking these practices to protect user experience and privacy.

As a result, EasyList tightened its definition of "self-promotion," and sponsored ads promoting third-party products are now blocked as it applies strict filtering criteria to maintain consistency. 

While this is detrimental to retailers, EasyList blocks sponsored ads as one way to potentially protect the user experience. By blocking retail media ads, it helps users avoid scenarios where paid advertisements inflate prices and reduce the quality of search results, protecting the user experience. It's also a cautionary tale on what can happen when revenue is prioritized at the expense of the user experience. 

But not all hope is lost for retailers. 

Here’s something to consider… 

EasyList vs. eyeo’s allowlist product

An allowlist, in the context of eyeo and ad-blocking technology, is a researched and independently-governed list of ads that meet the criteria of the Acceptable Ads Standard. eyeo’s allowlist enables publishers, advertisers, and ad networks to display compliant ads to users who have ad blockers installed but allow Acceptable Ads.

While EasyList strictly blocks ads without exceptions, eyeo's Allowlist (Acceptable Ads) allows nonintrusive ads that meet specific criteria. The Allowlist supersedes EasyList, but only for ads compliant with the Acceptable Ads Standard.

Why is this good for retailers looking to improve the user experience and generate some revenue?

The game changer for retailers and publishers

eyeo works with retailers to create sustainable monetization models. While they don't control what websites or ads get blocked by EasyList, they do control what can be allowlisted. If a retailer adjusts their ads to be Acceptable Ads Standard-compliant, they can be added to eyeo's exemption rules, which supersede EasyList, allowing the retailer to monetize ad-filtering users and curate a better browsing experience for their users. 

This is a balance, not a trade-off between user experience and revenue. By allowing less intrusive ads through the Acceptable Ads program, retailers can show users ad types they are open to seeing. While other ad blockers on the market leverage absolute ad blocking or charge users, our extensions are free to use and our users understand the value exchange between premium content and an ad-filtered experience, thereby giving retailers that chance to monetize almost all of their users.

And if you’re considering ad-reinsertion or circumvention, here’s why you shouldn’t. 

Ad reinsertion & circumvention: Why it fails

Ad reinsertion and circumvention techniques, used by advertisers and publishers to bypass ad blockers, generally fail due to constant updates from EasyList to maintain ad-blocking effectiveness. These methods, which include obfuscating ad scripts or injecting ads dynamically and are typically provided by third-party vendors, often degrade user trust and can lead to more aggressive blocking. Furthermore, creating a sustainable, in-house alternative is costly and resource-intensive, requiring continuous reactions or creating countermeasures to EasyList updates. There's also the cost of developers to consider while playing this cat-and-mouse game. 

All in all, EasyList plays a vital role in shaping the modern web experience by blocking as many  ads as possible. While ad blocking benefits users, it also challenges retailers. Finding a middle ground is possible, and solutions like eyeo's Allowlist attempt to bridge the gap, giving retailers a way to improve the online experience for users and address this hidden audience of ad-filtering users.

Photo credit: Freepik