Brazil's diversification crisis shows the limits of walled gardens

Brazilian advertisers concentrated in walled garden platforms face rising campaign costs, while diversification attempts through agencies frequently result in poor returns or fraud, according to an industry analysis. Many agencies resell inventory from upstream providers with multiple margin layers; some supply is legitimate but expensive, while some is fraud disguised as open-web reach. Advertisers pay more for worse outcomes, fueling a market-wide trust problem. The article advises marketers to vet partners on vertical integration, machine-learning quality, independent traffic verification, and demonstrated incremental lift, enabling direct relationships and reduced dependence on walled gardens.