The digital advertising space has experienced a bumpy year as marketers, brands and agencies struggle to adapt to the increasingly complex world of data-driven advertising and the growing technology stacks needed to navigate it effectively. The current landscape of ad tech, dominated by programmatic solutions and sometimes opaque business practices, has proven itself prone to misfires, mistakes and a lot of outright ad fraud – not to mention growing brand safety concerns. At the IAB’s annual Leadership Summit this month, Unilever’s chief marketing officer, Keith Weed, representing the second largest advertiser in the world, threatened to pull advertising from publishers like Google and Facebook unless those publishers can deliver more guarantees around brand safety and transparency. Unilever, which owns brands…