A Puzzlement

I took Rita to her regular writer's workshop at Einstein Bros Bagels. I placed my order at the back of the store (cinnamon-apple coffee cake) plus coffee for each of us. The clerk asked my name (and I immediately thought, what do you need my name for? You gave me the cake already.), I named myself, and proceeded to pay. Oh, no, she says -- pay over there (oh, yes, that's right -- I've been through this before. We used to pay up front, now we pay at the end. Why can't I remember these changes? And, of far greater importance...)

Why did this Einstein's change things? (Maybe other Einstein's* have done the same thing. Come to think of it there's one way down south where you pay at the end -- but I think that's always the way things were at that store.)

To complicate the ponderings, the Quiznos across the parking lot from the first Einstein's mentioned (which brings up another puzzlement -- see the next, subsequent post), also did a switch. Only, it was in reverse. We used to pay at the end, now we pay at the beginning -- as soon as we order.

Can anyone explain?

*Another question: Should this read, "Einstein'ses have"?