Placed CEO David Shim says demand for offline attribution at a tipping point. Greg Sterling on April 12, 2017 at 12:17 pm Retail makes up the largest category of internet ad spending, representing about 21 percent of total revenues, according to the most recent IAB report — or roughly $15 billion annually. That’s why the … Continue reading Cost-per-visit ad models, offline verification set to shake up online advertising →