why are there puppy mills?

There are puppy mills because the people that sell the puppies want to get rich in profit. Those people sell the puppies for very high prices. They are very selfish people and they don't care about the dogs, all they care about is money. When you buy a puppy from a pet store, you might not know where that dog came from. It came from a puppy mill. When you buy that puppy, it supports puppy mills. That is why you need to buy a puppy from a humane society or a qualified breeder.