ATLANTA, Georgia (CNN) -- George Augustin is looking for "the one." He strolls past the 50 cinder block and glass cages that stretch across the Atlanta Humane Society's large dog room, just as he has many times before.
Puppy Jackson is featured as the "Spotlight Dog of the Day" at the Atlanta Humane Society.
When he leaves without a new companion, shelter workers are not necessarily sorry.
"Often, people come in several times before they find the perfect dog for them -- which is actually what we would hope they would do," says the shelter's public relations manager Kari Bogosian. If adopters make a hasty decision, she says, "They end up unhappy with the dog and return it."
Finding the right fit between human and animal is a top priority at shelters across the nation, which are marking October as "Adopt a Shelter-Dog Month." Watch why shelter dogs make great pets »
Picking a pet is an enormous decision, "right up there with choosing a house or buying a car," says Gail Buchwald, senior vice president at the American Society for the Prevention of Cruelty to Animals.
One of the biggest mistakes a potential pet owner can make is judging a dog on appearance. Buchwald says, "This is something that goes much deeper than skin-deep, or fur-deep." See some not-so-typical dogs »
Shannon Boyer of the Arizona Animal Welfare League says temperament, rather than appearance, should be No. 1 priority.
"They stop being cute when they start exhibiting behaviors that don't meet your expectations."
As many as 7 million companion animals enter shelters each year and a large number of them are pets surrendered because of what divorce courts would call "irreconcilable differences." The dog is too energetic, too quiet, too noisy, too shy, too assertive, or doesn't get along with other pets.
At some shelters, staff are trained to make sure the dog you choose fits in with all the members of your family, including other pets. Every member of the household should have a say and ideally will take part in the selection process. Many shelters even set up so you can bring your current pets in to meet the new dog on neutral territory.
More than 250 shelters across the nation use the "Meet Your Match" program. Adopters fill out a questionnaire to determine their personality type, then they are introduced to dogs with a compatible "canine-ality."
Many adopters find out the breed or type of dog they "think" they want, wouldn't be a good fit.
Apartment dwellers tend to come in looking for smaller dogs, assuming they'll be easier to care for. But Buchwald says bigger, "couch potato" dogs like St. Bernards and greyhounds adapt very well to small quarters.
Some shelters are seeing a boom in small dog surrenders. "Thank you, Paris Hilton," says Virginia Dalton of Seattle's municipal Animal Shelter. She says certain small breeds, like Jack Russell terriers, need lots of action and plenty of room to displace all their energy.
On his recent visit to Humane Society of Atlanta, Augustin said he was thinking he'd love having a Jack Russell. When it was pointed out he was searching in a room filled with large dogs, Augustine smiled and said he was keeping an open mind. That's smart thinking, according to Candice Eley of the San Diego Humane Society, who says, "Bringing home a new pet should never be an impulse decision."
You should give equal thought to where your dog is coming from. When it's time to get a new companion, many people immediately head to the pet store or breeder, assuming animals that are up for adoption have a questionable past.
"Shelter-dogs are often thought of as society's rejects," says Shannon Boyer of the Arizona Animal Welfare League. But surrendered pets rarely have medical or behavioral problems, according to Dayna Reggero of Denver's Dumb Friends League.
She says the issue usually lies with the owner who must surrender their beloved pet because they have allergies, have become too ill to care for it, or can no longer afford it. A number of shelters report a surge in surrenders they attribute directly to the current economic crisis, with some dog owners no longer able to pay for pet food or veterinary care.
Any dog that's placed up for adoption at Boyer's shelters has gone through rigorous physical and behavioral screening. They are vaccinated, spayed or neutered and micro-chipped. Staff members spend up to seven days working with the animal before it is cleared for adoption. Boyer says that allows the shelter to get the best sense possible of who the dogs are, "So we can meet their needs as well as the family's needs."
All that comes for a bargain price, usually between $50 and $175. Compare that to the cost of purebred puppies, which can reach into the thousands of dollars, with no guarantees about the dog's health or temperament.
Eley says most pet stores think of each animal as a "potential sale" rather than a loving companion who deserves to be placed with just the right family.
Purchasing from a store or backyard breeder also promotes the puppy mill industry, which churns out millions of puppies each year. Buchwald says inbreeding and dismal conditions at many of these mills result in, "puppies that are really a crapshoot health and genetics wise."
Meera Nandlal of the Houston SPCA says puppy mills and pet stores are not only the major cause of pet overpopulation, they often abuse and mistreat their animals. By adopting, she says, you are "contributing to animal welfare" by helping put those operations out of business.
You may also be saving a dog's life. Millions of dogs are euthanized every year because shelters lack space or resources. Every adoption empties a cage that can be used for another dog. Dalton calls adopting from a shelter a type of "recycling." She says there are "so many safe, lovable sweet animals out there. Everything from purebreds to bizarre mutts." She says they are "too good to waste, and we waste too many in this country."