About 98 percent of the puppies and kittens sold by pet stores come from puppy/kitten mills. Puppy mills are greedy and selfish operations. Owners run their puppy/kitten mills purely for profit and not for the love of the animal or any particular breed.
http://www.change.org/petitions/mayor-jerry-sanders-and-san-diego-city-council-members-pass-an-ordinance-to-ban-the-retail-sales-of-canines-and-felines#share