Answer: restaurant's reputation.
By improving safety standards, along with creating regular customers, the restaurant's reputation will increase, making it easier for it to be publicized. It widens all the possible means for it: from giving out invitations on the street, using social media or even Google's services to promote a business.
This could also make for a more profitable product. Based on the high-quality standards and service, prices could potentially be raised (within a reasonable margin), which can lead to providing an even better experience while in the restaurant.