[Siegmund]

That's going to vary place to place and dealer to dealer... but as a rough estimate... how long does the shuffle take? If it's 15 seconds longer than pushing a button and grabbing a new deck, that's time to deal 3 or 4 extra hands an hour.

The cards also last much longer - shuffles are very destructive, especially the cards are forcefully bridged and snapped together after each riffle. That literally scrapes the spots off them. The shuffling machines let the cards fall into place without ramming them together.