Old F1 venues

Was watching some stuff from the Jim Clark weekend at Hockenhim earlier, and was interested in these fairly recent F1 venues, the infrastructure put in and the fact they no longer run F1 how on earth do they make any money!!

Paul Ricard, Hockenheim, Magny Cours, Turkey, I eman what is Zandvoort going to do now, they spent millions getting it up to scratch, did they make money?