12 Apr 2024 Search

(update 22 Apr 2026: update links, copy edit)

(update 16 Mar 2025: add links, add slide from Advertising: Who Cares?)

According to a survey done by Censuswide for Ghostery, a majority of Americans now use ad blockers. Yes, it looks like a well-designed survey of 2,000 people. But it’s hard to go from what people say they’re using to figuring out what kind of ad blocking setup they have in place when they use the web.

  • Are they answering accurately? People might be under- or over-reporting their use of ad blockers. Under-reporting because they don’t want to admit to free-riding on ad-supported sites, or over-reporting because install an ad blocker is now one of the typical Internet tips you’re supposed to do, like not re-using passwords and installing software updates when they come out. People might be trying to look more responsible. When the FBI says you should be running an ad blocker to deal with fake search ads, and the IT department at CERN says, Block ads, stay clean, that puts a certain amount of pressure on people.

  • Are they using an honest blocker with real protection? The ad blocking category has a lot of scams, including adware and paid allow-listing, so most of the people saying yes are not getting the blocking they think they are. (The company that owns the number one ad blocker makes a business out of selling exceptions from blocking. Senator Ron Wyden wrote a letter to the FTC asking them to investigate the ad-blocking industry back in 2020, but no action as far as I know. In the meantime you can check your ad blocker using a tool from the EFF.)

  • How much of their browsing is on the browser or device that they had in mind when answering the survey? It’s a lot easier to install an ad blocker on desktop than on mobile, and people have different habits.

  • Is protection being circumvented by server-to-server tracking? Ad blocking has been a thing for a long time, so the surveillance industry has gotten pretty good at working around it. Facebook has responded to Apple ATT and to blockage of their tracking pixels by rolling out server-to-server tracking, which avoids any protection on the client. Google and other companies also have server-to-server tracking. (And they’re trying to get attribution cartel tracking into the browsers.)

  • Maybe they really just don’t like ads in general. Lin et al. found that running an ad blocker leads to fewer reported regrets with purchases and an improvement in subjective well-being. Maybe the simple explanation is just Advertising Makes Us Unhappy. In a study by Miroglio et al., The Effect of Ad Blocking on User Engagement with the Web, users who installed an ad blocker spent significantly more time in the browser (+28% more than control).

  • Maybe ads are just worse now. According to a presentation by Michael Farmer at the Advertising: Who Cares conference, the people who make the ads are having to make more and more. Maybe the ads carry less information for the same amount of interruption and annoyance, and that’s why it make sense to block them. (And it’s not just about the rise of content creation software—most of the increase happened after agency processes had been digital for a while.)

The number of ads made by each agency employee increased from 3 in 1983 to 311 in 2019

The second most newsworthy part of the new Censuswide survey is why people say they’re using an ad blocker. Protect online privacy is now the number one reason, with block ads and speed up page loads coming in after that. I’ll leave the most newsworthy part to the end. I know, I know, some people are going to reply with something like, yeah, right, these ad blocker users are just rationalizing free-riding on ad-supported sites, like Napster users making bogus fair use arguments instead of paying for CDs back when that was a thing. But, as Lars Doucet points out in Ad Blockers and the Four Currencies, it’s more complicated than that—many people get a positive integrity dollars bonus from punishing or disincentivizing a violation of privacy and honesty norms. So any guilt over free riding can get balanced out by positive feelings about denying surveillance data to some kind of bad people on the Internet. In order to understand the ad blocker survey results, we have to put the survey in context with other research. Compare to Turow et al. on attitudes to cross-context tracking, and to an IAB Europe study that found only 20% of users would be happy for their data to be shared with third parties for advertising purposes.

It looks like the privacy concerns are real for a significant subset of people, and part of the same trend as popular US State Privacy Legislation. Different people have different norms around ad personalization, and if people can’t get companies to comply with those norms they will get the government to do something about it. For companies, adjusting to privacy norms doesn’t just mean throwing privacy-enhancing technologies (PETs) at the problem. Jerath et al. found similar levels of perceived privacy violations for on-device ad personalization as for old-fashioned cookie-based tracking. PETs have different mathematical properties from cookies, but either don’t address other problems or make them worse.

Companies deploying PETs are asking users to switch away from ad blocking and to trust that the companies will do complicated math honestly—but they’re not starting from a position of trust. When users have the opportunity to evaluate the companies’ honesty in a way they do understand, the companies don’t measure up. Most people can look at an online map of their neighborhood and spot places where a locksmith isn’t. And it’s easy to look up a person on a social site and see where there are enough profiles that not all of them can be real.

screenshot of several fake Facebook profiles, all using the same two photos of retired US Army General Mark Hertling

The biggest problem with PETs will be that the Big Tech companies do both easy-to-understand activities—like scams, fake profiles, and union busting—and hard-to-understand activities, like PET math. I see you served me scam ads and a map with fake companies in my neighborhood, but I totally trust your math to protect my privacy — no one ever If you don’t know if the PET math is honest, but you can see the same company acting dishonestly in other ways, then it’s hard to trust the PET math. (Personally I think the PETs are probably meeting their mathematical goals, but they’re being rolled out as part of a larger program to squeeze out legit publishers and other smaller companies, and to cause more privacy harms in a harder-to-regulate way.)

In AIC polls, confidence in Amazon, Meta, and Google has fallen since 2018.

(source: How Americans’ confidence in technology firms has dropped: evidence from the second wave of the American Institutional Confidence poll) It would be unrealistic to expect PETs to shift people’s attitudes much on privacy concerns, or to affect ad blocking rates.

The most newsworthy result from the Censuswide study

Maybe another variety of trust issue is behind Censuswide’s most newsworthy data point: experienced advertisers (with 5 or more years of experience in advertising) are more likely to run an ad blocker than average. (66% > 52%) Reminds me of how experienced email users were early adopters of spam filters—the more you know, the more you block. Between sketchy placements, bogus reports and a your call is important to us approach to advertiser support, the advertisers are having a much worse advertising experience than the rest of us. The Censuswide survey (full report PDF) also shows that more experienced advertisers than ordinary users believe that the Big Tech companies are likely to abuse data.but realistically, who knows if they are or not?

The Tragedy of the Commons is bogus when it comes to actual traditional practices for managing common resources, but it is a thing within large companies. Individual product managers are incentivized to achieve short-term goals either at the expense of other product managers, by dishonest practices that spend down the (common across the whole company) reputation level, or both. For example, within the same large company one business unit can achieve its goals by selling licensed copies of e-books, while another business unit can achieve its goals by running ads on infringing copies of the same titles. Big Tech fans often ask, if these companies are so distrusted, why do people keep using their products? But another question is, if these companies are so trusted, why do voters keep asking the government to take over managing their products? Privacy settings are hard for users to figure out and easy for companies to override, but a vote for privacy is easier and sticks better. (and possibly the one thing that a bitterly divided nation can agree on)

Doc Searls called ad blocking the biggest boycott in world history back in 2015. Ad blocking looks like a response to creepy practices (or perceived privacy violations if that works better for you) and those practices are part of a more general scam culture crisis. Tressie McMillan Cottom writes,read the whole thing

Scams weaken our trust in social institutions, but their going mainstream—divorced from empathy for the victims or stigma for the perpetrators—means that we have accepted scams as institutions themselves.

I can’t see any one big policy solution for surveillance advertising, tech oligopolies, or the broader scam culture problem. All of that stuff would have to change in order to move the ad blocking numbers. It’s going to take a variety of approaches, maybe including a surveillance advertising ban, maybe surveillance licensing, maybe a Pigovian tax on databases containing PII, maybe breaking up Big Tech firms. So far the most promising approach seems to be state laws with private right of action, which is one of the reasons I’m so optimistic about Washington State’s My Health My Data Act. My experience on a jury (not an ad-related case) was the most productive meeting I have been in since I came to California. If surveillance advertising issues can grind their way through a few jury trials, where lawyers have an incentive to explain what’s going on in an accurate, comprehensible way, then both surveillance marketers and privacy nerds will be able to reset how we approach this stuff based on more common sense.

More: Sunday Internet optimism