There is a belief which says that dropping salt brings bad luck. This fact is based on the value that this substance had in the past. Nowadays, it is still believed that dropping the salt brings bad fortune, and in order to neutralize this negative effect, one should take a bit of the dropped salt and throw it over the shoulder, backwards.
In this video, the fact of throwing the salt backwards over the shoulder keeps bad luck away. However, during this action, the effect goes to the person located right behind.

http://cargocollective.com/AlReves/

Add

bringing luck back