The best way to put an end to puppy mills is to educate people about the various breeds and their personalities and jobs and not try to increase demand to reduce supplies.
A responsible breeder breeds no more than 1-2 litters a year and makes sure the puppy buyers understand what it truly means to own one of those puppies. And they try to stay in touch with the buyers and be willing and able to take the puppies back if the home doesn't work out no matter what the age of the pup.
If the breeder has a breed that is more easily placed in homes (say a labrador breeder or yorkie breeder), I feel that the same ethics should apply. I know many who breed those breeds and they are just as strict and adhere to ethics as my Scottie and Bouvier household. Unfortunately, there are many out there that give "popular breeds" and breeders a very bad rep.
We should try to re-direct the "CostCo Mentality" of "Same or similar product for Less" or "Craigslist Mentality" of "Sorta Like what I wanted but for less" ideology behind getting pets if we want to make sure we have healthy pets and the Lifetime Guarantee Terms and Conditions are in the animal's favor. "I want a Lab but I don't want to pay x-amount of dollars for one" is what keeps puppy mills in business. Shame on us humans for being cheap and looking for a bargain on living beings!!!!
I detest puppy mills, as well. The biggest challenge is when we have to fight for the right to have successful breeding programs that might, at times, have the same # of animals that define "puppy mill" when it may be a responsible breeder's home or kennel. I won't go into the mathematics, but a responsible breeder could fringe on "puppy mill" definition one or two times a year based on when females in the same pack come into season. Are you a woman? Work or live around other women? Ever experience the timing of menstruation with your colleagues? The same happens in dogs and cats.
That is why we fight for the laws that the HSUS tries to push ahead and put limitations on the # of animals on property. A couple bitches that came into season near each other and had healthy litters at the same time, a few horses, cats, a few male dogs... suddenly without ever harming one animal's life, you're now breaking the law if the HSUS passes laws in your state and the local authorities could seize your lactating bitch, puppies, and every critter on your property. No thanks. Make folks adhere to already-in-place-local-law
I, too, detest puppy mills. But I do support responsible breeders if we're to continue to have pets in the United States.