MetaX

Early blockchain-based advertising transparency venture (adChain)

MetaX is a Los Angeles-based advertising technology company that applied blockchain technology to transparency and fraud problems in digital advertising. Co-founded by Ken Brook (also CEO of the video ad tech firm VidRoll), it built adChain, an open protocol on the public Ethereum blockchain developed with ConsenSys, as a shared record of ad campaign data such as impressions and clicks; it piloted adChain with the Data & Marketing Association in 2017. In May 2018 MetaX launched the adChain Registry, a community-curated whitelist of ad-supported publisher domains that it described as the first Token Curated Registry on a public Ethereum blockchain, using its adToken (ADT) for nominating, voting on and challenging listings. It also launched Ads.txt Plus on adChain. Public coverage of MetaX and adChain largely ends after 2018; no acquisition or shutdown has been reported.