It is becoming common practice for insurance companies and the emergency services to advise that business burglar alarm systems are monitored at all times. A burglar alarm is unlikely to sound when anybody is in the building, with the occupants acting as a deterrent to the majority of potential intruders but once the building is empty it's a different story.
It could easily be argued that the security of an establishment is the most important thing next to sales. Theft and robbery could easily put your entire business in jeopardy.