When the postcard was issued in 1873, the custom of sending postcards as nengajo spread rapidly because New Year's greetings could be sent simply and inexpensively.
1873年に郵便はがきを発行するようになると、年始の挨拶を簡潔に安価で書き送れるということで葉書で年賀状を送る習慣が急速に広まっていった。