It sounds like the start of a bad joke. Why do magicians like Ferrero Rocher? Ignoring the fact that they taste nice, why would a magician be keen on one of these tasty treats...
Well, maybe this will give you a clue...
Yes - Ferrero Rocher boxes make the perfect containers for spare playing cards! Often when I'm doing a card trick and ask someone to write something on a card they say "Are you sure? Won't that ruin the pack?" This is quite understandable as most people just have one (probably ancient) pack of cards somewhere in their house. However, as a professional magician, I always have literally hundreds of packs about the place and thousands of individual spare cards, as you can see from my "spare Aces" collection in the picture above.
Thank you Ferrero Rocher for making lovely chocolates and putting them into perfect card-sized containers!