What i do is slowly hire the manage sales, destroy the two easy places, then try to have your sales up in the beginning, then max out your zombies and get your revenue upgrade high enough that you dnt have to worry about your money fall behind. hiring too quickly will destroy you. then, when you have your original amount of money(on hard, i advice you to get your money to $50,000 to go in battle or hire more people) then go and conquer the world, but slowly. you will have to repeat these steps when you upgrade the capacity of your employment hiring.
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