pubX raises $5m and buys Compliant to filter bad inventory for AI buyers

PubX, a UK ad tech start-up, has raised $5m in a Series A round led by Chicago Ventures, AdExchanger reported on 6 October. In the same move it bought Compliant, a media quality firm co-founded by former Unilever and P&G marketers. Neither side disclosed the price.

Andrew Mole built pubX for publishers before adding buyers

Andrew Mole co-founded pubX in 2020 and runs it as chief executive. The company started on the sell side, helping publishers price and sell their ad space. This year it added software agents that buy media for brands and agencies. That puts pubX on both sides of the deal.

The platform runs on the Ad Context Protocol, or AdCP, an open standard for software agents that trade ads with each other. PubX is a founding member of AgenticAdvertising.org, the group behind it. Mole told New Digital Age that agents “let us finish what programmatic started”.

Compliant scores inventory before pubX agents bid

Compliant builds data integrity and CTV quality indexes. They separate premium impressions from poor ones. Inside pubX, those scores will act as a filter before a bid goes out. Compliant keeps its own brand.

Jamie Barnard, Compliant’s chief executive and a former Unilever general counsel for marketing and media, becomes pubX president of global demand growth. He told AdExchanger that the biggest barrier to agent tools is doubt over “whether they can be trusted to make the right decisions”.

Buyers share that worry. IAB Europe found 58% expect agentic ad buying at scale, while platforms such as Microsoft Curate are adding Copilot to private deals.

The $5m goes to the US and to brand-side sales

PubX says the money will fund a US expansion, a team that sells to brands and agencies, and the work of plugging Compliant scores into its buying agents. Five million dollars is a small round by ad tech standards. It buys a US foothold and a buy-side figure with Unilever on his CV, not a large sales force.