Advertising technology is at the core of the modern internet economy, something that has turned it into a confusing and increasingly fraught battleground of competing interests. Users don’t like intrusive ads and respond with adblockers, publishers are at war with these blockers to get the ads through while large communications firms are now trying to undermine the whole ad-serving model for strategic reasons.

The ads in question include banners, pop-ups and pop-unders, all of which interrupt websites to the degree that users notice something is happening. It seems that everyone either loves or hates them, or simply wants to control how they are served. A lot is at stake with vast sums of money resting on how the chips land on this one. Google alone can point to almost $60 billion (£40 billion) in revenue from serving ads during 2014 so anything that disrupts this will elicit a strong response.


As we noted in the recent article on privacy tools, adblocking also has security benefits, for instance greatly reducing the hazard of malvertising, which uses pop-up and redirects to point users to malware and worse. In some cases, blocking also benefits privacy by stopping advertisers gathering data on individual browsing habits in order to serve targeted, ’programmatic’ ads.

The contentious issue is how adblocking is implemented. The traditional way is to load a plug-in on each device that allows the user to manage which sites are allowed to show ads and which aren’t. It’s a bit laborious but has still become a growing nuisance for advertisers and the publishers that depend on serving ads but the overall number of users for these tools remains small. In an effort to wean users off them, publishers increasingly throw up polite-sounding messages if they detect a user is browsing with a blocker installed, asking them to consider turning it off.

The question is politely-worded but it’s really a way of reintroducing the hassle that adblockers were supposed to avoid in the first place. Some publishers – The Washington Post and CNET for instance – have even started to drop users who insist on using such tools, a tactic that underscores that this issue is turning into a high-stakes game of chicken.

How adblockers work

All blockers interrupt ads they detect being served from pages but there are different techniques for achieving this. The default and most efficient technique is to block the HTTP ad request as it is made although some instead block content on its return journey. As the example of Three UK demonstrates (see below), ads can also be blocked at carrier network level while it is always possible, with some effort, to block common ad-serving domains using a firewall. It’s never been obvious whether many admins bother to do this.

From the blocking side, stopping advertising can be a complex undertaking and actually pulling it off effectively requires building a maintaining a list of ad platforms, trackers and beacons and applying this in real time to web traffic. These days, the quality of adblocking is high.

Network blocking – Three UK

Recently, in an intriguing and threatening move, mobile network Three UK has announced that it plans to implement adblocking at network level using technology from a startup called Shine. On the face of it you can see the company’s point. Ads and web tracking tools consume bandwidth on mobile networks in a way that can cost subscribers money. Programmatic advertising has always been especially unpopular on mobile devices. Three says it is simply sticking up for its customers.

This move has major significance because network-level controls put the power to block ads (or not) into the hands of providers and third-parties rather than users. With rivals UK mobile carriers EE and O2 also reportedly testing network-level blocking, alarm is spreading that a power grab is underway. The argument against network-level ad control is mainly that replicates what software plug-ins do in a way that takes control away from end users. Might Three’s adblocking simply be a way of shifting the ad gatekeeper from the website to the network and its partners?                

Network blocking isn't new although it has until now been something limited to desktop computers. In 2013, French ISP Free tried to block ads through its DSL routers to make a point about internet neutrality, before being forced to back down.

Apple and Android

A second if exaggerated issue has been the attitude of mobile platforms themselves, specifically Apple, which in 2015 for the first time introduced the possibility of adblocking apps in iOS 9. The move was interpreted as a major shift designed to take aim at ad giant Google although it’s equally true that adblocking has been available on Android for years despite that not being in Google’s interest.

Apple makes money from apps sales – most popular iOS apps including adblockers are paid software - and charges developers to appear in the App Store. Techworld presumes that Apple's own nascent ad platform is not blocked by these apps.

Programmatic advertising

How did it come to this? After all, internet advertising was supposed to be the engine allowing publishers and e-commerce firms to thrive and not something that started a virtual war between with end users and carriers.

The answer is that advertising, once relatively simple, has turned into a complex market that is increasingly automated. The principle of this form of advertising – about a quarter of the ad market and growing rapidly – is targeting viewers in real-time according to behavioural criteria and selling through advertising platforms. This is a world driven by algorithms and computers not sales people. A lot of publishers are unhappy about the opacity of this way of buying and selling ad space but there is no doubt that it is a logical outcome of a machine-driven world.

Critics argue that the incentive to serve more targeted ads to fulfil the algorithmic way of understanding traffic has simply led to far too many ads aggressively chasing ever more reluctant consumers. It’s not clear that network-level blocking will change any of this at a fundamental level but by creating winners and losers it could lead to a rapid consolidation among the ad networks themselves. An example of this is how large firms such as eBay and Google have entered the programmatic market, with the latter now serving them through its DoubleClick system. Would anyone bet against Google?

Acceptable ads

The catch in all this is because most desktop and many mobile adblockers don’t charge end users and have to fund their business model in other ways. An example of where this can lead was the decision in 2011 by the makers of the market leading browser AdBlock Plus to start whitelisting ads that met certain criteria. The company always offered the ability to turn this default option off but speculation grew that the German firm behind AdBlock Plus, Eyeo, was allowing some ads to be whitelisted in return for a share of the revenue. It was never clear exactly how this worked with AdBlock Plus only opening up in February 2016 about who pays and on what basis.

There has never been ‘pay-to-play’, the company said, with only advertisers exceeding 10 million incremental ad impressions on per month on AdBlock Plus being asked to sponsor. This structure meant that 90 percent of publishers were not asked to pay.

Regardless of how it works, the Acceptable Ads programme isn’t an argument against adblockers or AdBlock Plus per se but it is a warning that they don’t all work in the same way. It has led to controversy and lawsuits, with a number of publishers accusing Eyeo of running a ‘protection racket’ based on a conflict of interest (i.e. blocking ads but also letting them through for money).

Why mobile adblocking is the internet's next battleground – conclusion

An interesting coda to all this was the most popular app in the App Store in the hours after Apple allowed them in September 2015 on iOS 9 was an adblocker called Peace, created by Tumblr co-creator Marco Arment. Within days he’d had second thoughts and pulled it, offering refunds.

“Achieving this much success with Peace just doesn’t feel good, which I didn’t anticipate, but probably should have,” he wrote at the time.

Ironically, Arment had launched the app to block the ‘creepy’ tracking that has arrived with ads but ended up worrying more about the collateral damage on publishers who offer content free in the hope of attracting advertisers.

The success of the app seemed to frighten him but that might be the point – if adblocking is here to stay the question becomes whose adblocking will win out and in what shape or form will it allow advertisers to buy their way through to the end users.

The optimistic view is that the world will sort itself out eventually. The number of advertisers will fall in a beneficial shakeout, the remaining players will do a better job of targeting end users without pop-ups and intrusiveness on mobile devices and users will accede to turn off or turn down blocking. Advertising won’t disappear, then, but be better in a world which creates a new set of internet losers and winners.