In a plastic based society, having pocket full of change isn't the way to go. I don't recall the coins are something that I carry for a long long time. The coins are to be found in either car cup holders, or the plastic jug I placed nearby entrance door.
The "smart card", the micro-chip embedded cash card didn't take off in America, but it worked well in Europe when it was first introduced in 1990's/early 2000. I think having a superior communication infrastructure renders the off-line transaction (coins, cash smart card) less important.
I like to use coins to save our tax payer money, but couple things has to happen first
1. stronger pockets for all. better design of coins holder for purses
2. pricing structure need to match the use of coins when the basis for everything is near $1.00 mark - water, soda, chip, or lottery tickets.
3. machines accepts dollar coins
4. fewer credit card accepted vending machines. red box accept coins?/not credit cards?
