Hello,

I am planning to make some visitation cards, which is cheap where I live - about 2,5 euro for 100 of them.
I am thinking where to leave them - I work in Belgium. I'm thinking about 5 stars hotels, stations, cars... Where else?

Many many years ago I worked with a friend in Brussels. We went to a lot of 4 and 5 star hotels, talked to the door men and gave them a set of v cards. We made a deal that if a client made a booking because of the card, he would get commission.
We tried the same in Paris. We were shoo'd away at the fancy hotels with horrible looks on their faces because.. of course their hotel guests would never ever call an escort. What on earth were we thinking?   

at the time we worked part time. In Brussels it gained a few bookings. I don't know what would happen if you'd do it now.