It can be a net profit for the city hosting it, its really no different then any other tourist event. When Sweden hosted it last year the region that hosted it made a profit of 185 million sek, or around €20 million. The production costs for SVT was €14, 5 million(public service). Thats not including the value of the media exposure, that was estimated to be around 1 billion sek or + 100 million €.