This could be the natural next step for one click shopping. Obviously it'll be more difficult without textual or visual capabilities, but things like "Add gelato to my shopping cart"(as apposed to shopping list) would be huge for Amazon fresh shoppers and other products that aren't too ambiguous.
Another application: "Alexa, order a Dominoes pizza with extra anchovies. "
Another application: "Alexa, order a Dominoes pizza with extra anchovies. "