Unless a thorough background check is done on a prospective new owner, giving a dog away for free is not a good idea because you never know where it might end up.
Now you might be thinking the above video is a bit over the top alarmist but backyard breeders/puppy millers scouring the internet for online free dog to good home ads are way too prevalent. They're generally looking for younger, unspeutered animals to lock up in a cage to be used as breeders for the rest of their useful lives.
Recently, a rescue Toronto Animal Services South works with was able to save a female French Bulldog from a miller who frequently finds breeders from families giving away their dogs for free. The dog was one of a pair of Frenchies, and the miller was getting rid of her because she'd already been spayed but he wanted to keep the male because he was still intact. I wonder if the original family knows or cares that one of the dogs they gave away will likely be spending the rest of his life in a cage.
This Pug and Puggle pair at TAS-S came from a puppy miller from the same rural area, a farm west of Kitchener, as the miller who took the Frenchies. They walk well on a leash and they like people - not typical of puppy mill dogs who have limited to zero exposure to both - so it's quite possible these two were once family pets as well.
If they were once family pets, they've forgotten their no peeing indoors rule but who can blame them. A dog gets put in a cage for a few years and of course it learns to urinate and defecate where it sleeps and forgets everything else. With regular daily walks outside at TAS-S, maybe they'll have it figured out again before they are put up for adoption.
At first I thought these two lovebirds were a bonded pair but apparently the amorous feelings are a recent development due to the female being in heat. Once the attraction period is over, they will likely be separated and adopted out individually. Of course if someone wanted both dogs ... well, they are awfully cute together.
For adoption information on this dog and other dogs (and cats and other animals), please visit Toronto Animal Services.