My undergrad degree is in Biz Management with an emphasis in Personnel Administration (now called human resources), I don't remember much but I do remember a discussion about profit sharing during wage and salary class.
Basically, profit sharing is a con job (my words not the professor's)to make you feel more a part of the organization. You work hard so the organization does well and you get a little something for your efforts.
However, once you do expenses (glad our's is on operational....NWA wasn't and it was a REAL con job) the amount is so diluted that it can backfire. IE, when you get your profit sharing check you go ****! I honestly believe you're better off using your negotiating capital on the salary side. Gives you more to "give back" in the bad times

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Ferd <----------BUT, yes of course I'll take the check