The document analyzes how online advertising in Poland was affected during a week of national mourning following the plane crash that killed the Polish president and others. It found that many advertisers suspended their online campaigns, leading to a 54.5% drop in tourism ads, over 50% drop in food ads, and decreases of 20-35% across other industries. As a result, displays of common ad formats fell 92-86%, and click-through rates for those ads were halved. The period showcased an unusual situation where online traffic increased but advertising traffic drastically declined.