chancy trade; business with uncertain profitability
Refers to businesses where income is unstable and depends on popularity, trends, or luck. Often used for entertainment or service industries with high variability.
Restaurants are a chancy business, so they are easily affected by the economy.
night entertainment business; nightlife business
Specifically refers to bars, hostess clubs, cabarets, and similar nightlife establishments. This is the most common modern usage.
She works in the night entertainment business.
The nightlife business looks glamorous, but it's tough work.