My job duties included getting refills, pre-bussing (removing dirty and unwanted dishes when customers were still dining), sweeping, cleaning and setting tables for new customers, emptying bus tubs in the dishwashing area and occasionally seating customers. Well that first year I busted my ass. I made sure nothing was left undone or half-assed. Since the servers tipped the busboys out each night, I made sure the customers were always cared for. I figured happy customers led to larger tips for the servers. Larger tips for the servers led to, usually, larger tips for the busboys. It wouldn't always pan out that way but I felt my work ethic would also help me later as leverage.
After a year, an opening for a serving position was made available. I felt I had enough leverage to set my ultimatum. One night I spoke to my floor manager voicing my interest in the serving position stating that if I wasn't seriously considered for the position I would "leave and find a restaurant that would appreciate my work ethic more".

Have any of you set an ultimatum that actually panned out? Any instances when it didn't work out? Do you feel that it may have 'poisoned the well' in some cases?
I'd like to hear your stories.