The museum square in Vienna has repurposed a lot of these old vending machines to sell comics, zines, art prints, folded posters and other small gifts. The contents change regularly.
You insert a coin, and choose one door to open. Sometimes each door has the same thing, and sometimes each is different. Originally these would have had paper plates with sandwiches. They are still common in the Netherlands, selling late night deep-fried food.
I got one of these astronomy zines for my friend Melanie.