I was at the Zurich airport while I had a connecting flight to Barcelona from Belgrade. My friend and I briefly spoke about Zlatibor (a city in Serbia), 30 seco

I was at the Zurich airport while I had a connecting flight to Barcelona from Belgrade. My friend and I briefly spoke about Zlatibor (a city in Serbia), 30 seconds later I got an ad for a hotel in Zlatibor, in the middle of Zurich Airport. We never spoke about or searched for Zlatibor.