Two-thirds of brand marketers purchasing digital ads programmatically have moved all or some of that function in-house, according to new research.

The Interactive Advertising Bureau (IAB) surveyed 119 US-based brand executives representing media decision makers across 16 ad categories and found that 18% of programmatic buyers had already moved all programmatic buying in-house, while 47% had begun the process and planned to continue further down this path.

The main reasons for bringing programmatic in-house were ROI attribution (cited by 47%), better audience targeting (44%) and improved campaign effectiveness (44%).

WARC's monthly Global Ad Trends report recently estimated the cost of the 'tech tax', money paid to middlemen in the programmatic chain, at $30bn worldwide last year.

This Data Point was drawn from May's Global Ad Trends report, which focuses on search advertising.