Hmmmm, spent 6 plus years (spent 17 years in a company that went under and so I took a year off and found jobs were scarce out there) doing that working sometimes 3 bars at once for a total of 60 mindless hours a week - my specialty was doubles - I would go in 11 am Saturday morning - fly to another bar at 7 pm - and leave there at 3-4 am - ride my bike home to sleep for a few hours and be at work again at 10 am and the weekend ended at 4 am again - and so on Mondays ---- I slept).
Had some totally awesome nights, especially with some private parties (nothing like counting out $300-$400 in tips) and also had some days that totaled $11 - had some wild fights in my places, kicked more than my share out the bar (yep, I'm a girl and did it plus broke up fights), met some really great people - as well as some people who were ... not there. All sorts of bar stories actually. It was OK, had my fill of it though. I graduated on to managing a bar in a BAD side of the city, cooking and then working and managing the catering side of a well established cajun bbq place --- the latter was part time (owner wanted me full time) as I was reestablishing myself back into the office/purchasing system.
Fun, but ... that was enough.
In this small city - Mom & Pops bars, small clubs (larger clubs btw usually have a bigger rotation so getting a couple of shifts is it) - $40k? Nu-uh. And not benefits, although the one place I worked at was thinking about it - until the couple who owned the place hit bad times and so that ended.