What is a puppy mill ?

There are many websites that can answer this question, Prisoners for Profit is a good blog to start, and the Where do puppies come from website.

A puppy mill is a large factory where puppies are bred in small cages for profit, like battery hens.
It is currently legal to breed dogs in small cages for their entire life without any regard to their welfare. Breeding mothers are frighten, locked in small cages, with the sole purpose of producing puppies for the pet shop, internet and overseas markets.
In Australia these farms have anything from 20 to 1000 breeding females who are kept constantly pregnant or lactating in order to keep up with demand.

For more information visit paws for action