Ok, at this point I should probably explain, before I get forever typecast as a tight wad.
In Australia, a 20 year old worker gets paid the equivalent of about $16.00 per hour USD. That's the minimum wage. It doesn't matter if you wash the dishes, or wait on tables, your boss has to pay you at least this much. More experienced staff can negotiate for more pay. And yes, some customers will often leave tips, either directly, or throw some change into the tip jar.
Not only that, but the boss also has to pay an extra 9.5% to the employee, based on whatever they earned that week into a retirement fund for the employee, similar to 401k in the U. S. The employer has to pay the extra out of his own pocket and it applies to full time employees and casual employees.
So, with the minimum wage and the superannuation, the employee is guaranteed to get at least $17.60 USD per hour.
I've travelled around the world and I haven't noticed any significant difference in customer service anywhere, regardless of tipping. I've eaten at silver service restaurants in Europe, UK, and eaten at roadside stalls in places like asia and Jamaica.