Advertisers test blockchain to verify ad impressions

Advertisers and ad-technology firms are running pilots that log ad impressions and conversions on blockchains to prove a human saw an ad and to trace ad-driven actions to on-chain events. The experiments follow large-scale enforcement by a major platform in 2025, when it blocked 8.3 billion ads, removed 602 million scam-related listings and suspended 24.9 million advertiser accounts.

The platform’s safety system processes hundreds of billions of signals such as account age, behavioral cues and campaign patterns and prevents more than 99% of policy-violating ads from serving, according to its reports. Generative AI has enabled cheaper creation of fake ads, simulated users, bogus clicks and emulated devices, which has left some illicit traffic reaching large ad networks.

One pilot in Japan ran from July through August 2025. The test involved Hakuhodo, Tools for Humanity and LG Electronics and used World ID to verify uniqueness of viewers without revealing personal identities. LG’s blockchain ledger recorded each verified impression. More than 3,500 participants and ten advertisers across electronics, travel, food, cosmetics and education took part. The companies reported a 50% increase in click-through rates and a 15-point improvement in bounce rates for campaigns that used the verification flow.

A separate approach focuses on proving that an ad produced a real action. Coinbase acquired Spindl in January 2025 and integrated the on-chain ads and attribution platform onto Base, Coinbase’s Ethereum layer-2 network. Spindl traces a user journey from a web click to an on-chain event such as a wallet interaction, an app install, a token purchase or staking. The platform creates a ledger entry and a verifiable chain of custody that links ad spend to on-chain outcomes.

The two concepts address different measurement gaps. The human-verified impression model provides a cryptographic receipt that a real person viewed an ad. The verified conversion model provides a ledger entry that an ad led to a measurable on-chain event. Both use blockchains as immutable ledgers for audit trails.

Experts and vendors note limitations. A blockchain records the inputs it receives, so its trust depends on the verification layer that supplies those inputs. If identity or device verification is compromised, the ledger will record fraudulent impressions as valid. Confirming that a viewer was human, that the device was genuine, that the impression was viewable and that downstream actions were authentic is described as an oracle problem.

Privacy and regulation are additional constraints. Systems that use biometric methods or proof-of-personhood face scrutiny in markets where such data collection is contested. World ID separates proof of personhood from personal identity by design, but legal and consumer concerns vary by jurisdiction.

Platform control over measurement is another barrier. Major platform owners maintain their own measurement systems and have limited incentive to adopt a neutral blockchain receipt layer that could change attribution flows. As a result, early commercial use cases are appearing in crypto-native apps, independent connected-TV inventory, rewards campaigns, gaming and wallet-based commerce.

Market figures underscore advertiser interest in reliable measurement. Global ad spend was forecast at about $1.06 trillion in 2026, U.S. digital ad revenue reached roughly $294.6 billion in 2025 with programmatic advertising around $162.4 billion that year, and one analyst group estimated ad fraud losses could reach $172.3 billion by 2028. A measurement firm reported that bot fraud accounted for roughly 65% of fraud in connected-TV environments in 2024.

Pilots in Japan and on-chain attribution work on Base show that blockchain receipts can be integrated into existing stacks as a parallel audit trail. Wider adoption will depend on the reliability of verification oracles, regulatory decisions on identity verification methods and whether advertisers accept the additional infrastructure and costs.