
The ability to save and load decks of cards would save enormous amounts of time in addition to allowing players to share decks and Roll20 to sell them at the market and make more money :) The ability to merge decks would also be extremely useful. For example if you wanted a deck composed of two decks of standard playing cards then instead of having to construct all 108 cards from scratch, you would only have to merge two standard decks together. Big time saver, particularly if your game uses more than 2 decks.