When you list in the marketplace (left or right side), you now can increase the quantities of the listings. You will now see a drop down box which basically is a "duplicate X number of times" feature. The default value is 1 so that things stay exactly what you are used to unless you change its value. Lets say you change the value to 10 Listings in the drop down... that means it will now do 10 of whatever you were doing. This will save you a few clicks if you are doing lots of listings of the same quantity.