By driving more effective placement of ads, blockchain technology can
solve this significant problem.
The Problem With Online Ads
Web users today enjoy access to virtually infinite amounts of free
online content thanks to a simple paradigm: Website owners allow platforms like
Google AdSense to display
ads on the sites they control. The site owners receive payment based on the
number of page views or clicks that the ads receive. This strategy allows
content owners to generate revenue without charging visitors to view their
AdSense and other ad placement programs determine which ads to
show to which users through a combination of factors, which range from the
language of an ad, to the content of a website, to the personal interests of a
particular user. The practice of placing ads based on personal interest is the
main reason unrelated ads can appear on any given website. If a user visits a
few sites related to Caribbean cruises, for example, AdSense will identify that
user as someone interested in travel-related ads. Those ads may follow the user
as they browse to sites that don’t relate to travel, including illicit or
unsavory ones that the advertiser may not wish to associate with their brand.
Because Google places very few restrictions on the types of sites
that AdSense will work with, sites with content that many people find
objectionable may display ads served by the platform.
This process means mainstream companies may inadvertently end up funding
terrorist organizations. Somewhat less dramatically, a business may find its
ads displayed on sites that endorse political views with which the
business does not wish to associate itself.
Business owners reasonably view these situations as misuse of
their advertising dollars. They also risk backlash from customers who don’t
understand the complexities of online ad placement and assume that businesses
actively choose to buy ad space from objectionable sites.
Traditional online advertising platforms like AdSense do offer
solutions to these challenges. Advertisers can choose to have ad programs
exclude particular sites when placing ads. They can also block certain
categories of websites. These approaches are clunky at best, however. It’s
difficult for advertisers to anticipate and block every site or category of
site that they might not want to associate with. And if advertisers block too
many sites, they could inadvertently undermine the effectiveness of their
advertising campaigns by excluding non-objectionable websites where they could
reach interested users.
Blockchains: A Better Solution
Blockchain technology offers solutions to these digital ad
placement challenges. By enabling a totally new strategy for determining which
ads to display for which users, blockchains allow businesses to bypass the risk
of unknowingly advertising on sites to which they or their customers object.
Blockchain-based digital advertising is still maturing. But there
are multiple possibilities for integrating blockchains into ad placement
strategies. One of the most compelling concepts to emerge so far is that powering
the Brave browser. Brave
blocks traditional ads and ad trackers by default. In their place, the browser allows
users to view ads related to information of their choice. The ads are bought
and sold in cryptocurrency.
This approach upends the traditional digital advertising paradigm:
It restores power to users and advertisers, rather than allowing third-party ad
placement platforms to decide who sees whose ads. Blockchain-based advertising platforms
like Brave were designed to make ad placement more effective and private;
happily, they solved the problem of ads appearing on objectionable sites along
Instead of following users across the web and deploying complex
algorithms to decide which ads to display on sites that they visit,
blockchain-based ad networks make placement determinations based on the
expressed preferences of the users themselves.
Blockchains can also help to solve ad placement challenges by
providing a more reliable and transparent way for advertisers to identify where
their ads appear. In the traditional approach, only the ad placement companies
have the ability to track where a given ad is displayed. The companies can
choose to share this information with their customers (in this case, the
advertisers) if they wish, but they rarely do so directly. Instead, such
companies generally offer ad placement information as part of complex analytics
packages that do not necessarily expose the raw placement data.
Blockchain-based ad networks like adChain solve this challenge by using blockchains to
store information about ad placement. The advertisers can then track the data
in a reliable, open, non-obfuscated way. This approach not only makes it easier
for advertisers to identify ads that end up on sites they don’t want to
support, but also allows them to more easily assess the overall effectiveness
of their ad campaigns.
Finally, it’s conceivable that blockchain technology could be used
to establish community-based consensus regarding which sites should be excluded
from ad placement. For example, if the vast majority of advertisers and users
in a given community were to vote against displaying ads on a site associated
with terrorism, that decision could be stored in a blockchain so that ads would
not appear on the site in question.
The advantage of this approach is that it would allow advertisers
to automatically avoid placing ads on objectionable websites. Rather than
having to preconfigure their ad placement policies and hope that they yield the
desired results, advertisers and business owners could rely on the consensus of
the blockchain to decide where ads should not be placed. And because the
consensus would be decentralized, no primary authority would have the ability
to censor websites from ad placement lists.
No developers have yet begun work on community consensus solutions,
and there are limitations. The biggest obstacle is that this process would work
only in contexts with a high degree of consensus regarding which sites should
be blocked from displaying ads. In situations where a significant minority of
participants in the blockchain believe a site is not objectionable, for
instance, it would become impossible to determine whether or not to block a
Still, existing blockchain-based ad platforms offer a solution to
a problem that has long plagued advertisers. Because they eliminate the need to
rely on user tracking as a means of determining where to place ads, ad
placement processes based on blockchain technology are more transparent and
easier to monitor. And in the future, blockchains could even be used to tailor
ad placement in a fully-automated way on the basis of decentralized community
consensus about which sites are not appropriate for displaying certain types of