Relying on foster families to help place foster animals is a helpful tactic for shelters and rescues. Foster caregivers know their foster animals better than anyone and can make great matches. Plus, it keeps the animals from ever having to return to a shelter setting, reducing stress on animals and the staff's workload.
It's important to share open adoption principles with foster families and staff so they will consider a variety of suitable adopters, and not hold out for the "perfect" person who probably doesn't exist.
The Humane Society of the United States has created an Adopters Welcome manual to help staff, and foster caregivers remove barriers to adoption such as lengthy adoption contracts, restrictive policies, and unwelcoming interactions that may keep an animal from finding a loving home.