When they finally decide to adopt, most people want babies. They are sweet and playful, and we are used to shops and breeders selling only puppies. The idea of take an adult is somehow unnatural.
With age, the chances for adoption decrease, not to say that void. Truth is people just do not know the number of advantages of adopting an old dog. The American Society for the Prevention of Cruelty to Animals (ASPCA) offers 10 reasons to do so.
Truth is with each day reduces adoption chances for the old dogs reduce. So if you want to adopt, consider the above.