25 percent of shelter animals are purebreds. Rescues exist dedicated to every breed out there. Consider adopting a homeless animal of a breed you prefer instead of using a breeder or buying from a pet store.
Licensed and backyard breeders add to the mass overpopulation of cats and dogs in this country. Backyard breeders are people who breed dogs in their backyard, without knowledge of or appreciation of animals and simply to make a buck.
Pet stores purchase their animals from puppy mills where the animals are treated poorly; abandoned, killed, or sold cheaply once fertility wanes; and resulting in behavioral and/or health problems often times. Much more information can be found online if you are interested.
A card with those interested only in purebreds: