Everyone knows that most people in the service industry makes a living on tips. The base wage for most waiters and bartenders is barely above minimum. So, they depend on their tips to live. The debate on tipping is as old as the profession itself and as the cost of living in SF increases, it intensifies. It might help however to explain to the average bar-fly, how the whole thing works.
Larger bars have floaters who are usually paid hourly to pick up glassware.
They are usually not tipped. The barback is a necessary variable in the bar staff equation. It does vary from bar to bar. The discretion lies with the bartender and is usually based on the amount of tips received and the barback's work performance. Yes, we all hope that you'd think twice about undertipping, or worse, not tipping at all.