One grocery store at which I've shopped leaves a bell on the checkout belt when the cashier steps away. A sign taped to it reads, "Ring bell for service."
I've never been comfortable with this. I understand that the intention is to keep customers from waiting an uncomfortably long time. Still, I can't ring the bell without feeling as though I'm being rude. Typically, I make sure all of my groceries are on the belt, ready to be checked out first. Then, I look around for a cashier. If I see one, I'll make eye contact and say, "Hi!" If no one else is in line, I'll search aisles nearby for a cashier. I'll also do another quick scan of the general area. Then, and only then, if I still don't see anyone, I'll give the bell two or three short rings.
Even though I don't prolong the ringing, I feel like I'm summoning an elk. I don't want anyone, especially those who have always treated me well, to feel like servants at my beck and call. I hope the store comes up with an egalitarian solution.