In Japan, '39' is common text speak for 'thank you', due to how 3 (san) and 9 (kyu) sound when spoken out loud.
Source
During the 18th century, you could pay your admission to the zoo in London by bringing a cat or a dog to feed the lions.Source
In Japan, '39' is common text speak for 'thank you', due to how 3 (san) and 9 (kyu) sound when spoken out loud.
Source