Transparency ranks as the No. 1 barrier to programmatic adoption, according to new research from IAB Europe looking into how attitudes toward programmatic advertising are evolving. In particular, advertisers are increasingly demanding clarity on the tech fees charged by their partners. In order to alleviate cost concerns, nearly two-thirds of ad tech vendors say that they’re making investments to offer a more transparent business model. But a lack of transparency isn’t stopping buyers from buying. Programmatic spending is growing like a weed in Europe. IAB Europe estimates that programmatic revenue grew by 23% in 2019, topping 23 billion euros (just under $27 billion).