Cash bars are considered inappropriate by etiquette writers, on the grounds that it is inappropriate to ask guests to pay for anything and because true hospitality shares what it has.
Cash bars have their problems for caterers and venue managers.
While commonly seen in reception rooms, a cash bar indicates that the host believes the guests should have access to drinks, but is not willing to pay for them.
The host can set a time limit for an open bar, beyond which it reverts to being a cash bar.
A cash bar is the least expensive option for a host.
The remedy was transforming the large downstairs studio into a 135-seat, cabaret-style club with candles, tablecloths and a cash bar.