Do you say "yes sir/no sir" (or ma'am) to employees at Taco Bell

[MODU]

Yes, all the time.  You will be surprised by the increase in quality service you receive by being polite and expressing to the person serving you how much you appreciate their work and effort.  (I usually end up not having to pay for my drinks and/or get free substitutions on my orders as a result.)

I address anybody I don't know except small children as sir and/or ma'am, so yes.

This.

^^^^

[MODU]

Yes, all the time.  You will be surprised by the increase in quality service you receive by being polite and expressing to the person serving you how much you appreciate their work and effort.  (I usually end up not having to pay for my drinks and/or get free substitutions on my orders as a result.)

I address anybody I don't know except small children as sir and/or ma'am, so yes.

This.

^^^^

I think you've missed the point.  Here, calling someone sir or ma'am might be seen as patronizing.

There are better ways to show you appreciate someone's hard work and effort.  You could say something like "thanks a bunch, I really appreciate it.  Have a good day" accompanied by a warm smile.

Your initial statement might be correct, but the question didn't express that it was meant as patronizing.  So my comment remains valid.  Additionally, my comment reflects your seccond point.