Another result of simple math is that legitimate dealers cannot meet the public demand for popular breeds, particularly when a celebrity or a movie puts that breed in the spotlight.
The movie "101 Dalmatians" produced an enormous demand for Dalmatians. "Beethoven" did the same for Saint Bernards, and Paris Hilton for Chihuahuas. In each case, puppy mills geared up to meet the demand. But many families discovered that these breeds can present challenges as pets.
A hot puppy one Christmas season often means a glut of unwanted adult dogs the next year. Unwanted Chihuahuas were so common on the West Coast after the Paris Hilton boom, they were actually airlifted east, where there were more families willing to adopt them.
The Internet is full of complaints from online buyers who received sick puppies, or simply did not receive the puppy they saw in the picture. Puppy mills count on the human heart to be too soft to put that puppy back in the box and return it.
A better solution is to be patient. "You're taking in a member of your family," Menkin says, "who will be with you from eight to 15 years."