My $0.02..

If you're playing a dance there shouldn't be dead air between songs. However, if you're playing Nightclub/lounges there should be.

These two are not the same gig and nightclubbers may not want to dance 3 or 4 dances in a row with the same partner. Having a long enough break to get off the dance floor and have a drink is a good thing in a singles bar scene.