83 Kellogg Insight Based on insights from Brett Gordon Using Experiments to Get the Most Out of Your Digital-Advertising Budget Brands are demanding evidence that campaigns are working. Here’s what they should be asking. DIGITAL ADVERTISING CONTINUES its march toward dominance. In 2017, digital spending surpassed television advertising in the U.S. for the first time; by 2019, it overtook advertising on all traditional channels. And some estimates suggest that by 2023, digital could account for as much as two-thirds of ad spending.