http://www.petfinder.com currently lists 282 dogs classified as Pugs; adoptable pets in need of homes. Instead, most will be put to death to make room for the next batch. It's a lethal revolving door. 6-8 million cats and dogs will be killed this year. And you want to breed more because you think you can make a buck?
The only was to make a serious profit from breeding is 1) win a big dog show and sell sperm or 2) pocket the money you negect to spend on important veterinary care. A lot of people get this idea and think it will be easy income, but all they end up with are worthless papers (big market in selling documents to suckers) and another litter for the shelter.