[jonno]

When it comes to tips you’re typically talking about jobs that perform a “personal” service, Trim YOUR hair, shining YOUR shoes, bringing YOUR meal. These are things you don’t purchase ‘off the shelf”.

“Sure, but countless other jobs are fixed salary and yet people still do a good job.”

Sure, but don’t you think immediate rewards go a long way toward promoting morale & job satisfaction (e.g. “spot bonuses”) - especially for those with good attitudes who do above and beyond what is expected?

[Theoria]

Maybe, but peer pressure, ie not letting your coworkers down, is a big factor. That is why it is important to have a good environment of employees..

Take for example, chickfila, employees there don't work on tips, yet their service rivals any restaurant in the business.