Where do I start? Hmm... It comes down to two things really-- counting back change properly, and facilitating getting your change back in your pocket, purse, wallet, etc. If I buy something for say $12.53, and pay with a $20, the cashier should put $0.47 in my empty outstretched hand and say "13", and then hand me the bills counting "14, 15, 20". This doesn't work when they just hand you a few bills and then slap the coins on top. Also, what do I do with a stack of bills with coins balanced precariously on top with one hand since my other hand is holding my wallet? If the coins are put in my hand first I can kinda palm them while putting the bills back in my wallet. If they don't do this, I have to put my wallet down, pour the coins off the bills into my hand, stuff them in my pocket, and then put the bills in my wallet. Am I being too much of a nut case here? No.