From 250,000 passers to 5,000 memories: The real math of DOOH impactTo plan DOOH effectively it helps to walk through the full chain from Opportunity To See, or OTS, down to brand recall. A large screen along a busy highway might be presented as reaching 250,000 people every week. To plan DOOH effectively it helps to walk through the full chain from Opportunity To See (OTS) down to brand recall. These tests provide heat maps of attention, stopping power scores and brand recall predictions. On a highway screen with 250,000 weekly passers and four advertisers in rotation the outcome is closer to 1,000 to 5,000 people who recall the brand.