In China, 666 Can Mean Smooth Progress and 88 Can Mean Bye-Bye
One number can suggest smooth sailing, the other can sound like farewell in internet slang.

The Tim Ferriss Show · Lucky #888 — My Tour of Designing Luck in China, Japan, and KoreaIn China, 666 can mean smooth progress rather than evil, and 88 can mean bye-bye online.
One common explanation for 666 is sound. Six can suggest the Mandarin word for smooth, connected with the saying liu liu da shun, a wish for smoothness in everything, much like wishing a traveler smooth sailing. The sound link is disputed, with different pronunciations and explanations, even within China.
Separately, cash gifts tucked in red envelopes, called hongbao, may come in amounts such as 600 or 666, especially around Lunar New Year.
Eights work by sound, too. Online, 88 is shorthand for bye-bye, because eight eight, pronounced ba ba, sounds like the English farewell, a usage heard in mainland China and Taiwan.
Whether a number is lucky or unlucky depends on location, and dialects within China change how numbers are pronounced.
Questions people ask
Why would how a number sounds make it lucky?
Mandarin has many words that sound alike but use different tones or characters. When a number sounds like a lucky word, people may associate the number with that meaning, and the association can show up in gifts, prices, and slang.
What is a hongbao?
Hongbao are small red packets used to give money for Lunar New Year, weddings, and other celebrations. Red is associated with good fortune and protection, and the amount inside can carry its own wish.
Is 666 always lucky in China?
No. China has many dialects and regional pronunciations, so a sound association in Mandarin may not work the same way in Cantonese or another dialect. Number meanings can shift by place, language, and context.