Put nothing in your recipe, meaning no sugar, no lemons, and no ice. Rent suburbs, which costs nothing. The only things you need to buy are cups and other required normal supplies, and you still need to advertise. Now people will always buy your lemonade. Custumer satisfaction will drop, but for some reason your popularity and cash will go up. You may lose a bit of money in the beginning, but eventually you will start to make approximately 10 to 15 dollars a day.
