People need to connect their social networking, the same to our furry friends.
I have a border collie boy who lives with my family, he is an active, intelligent kid that can "read" from our eyes or gestures. We accompany him every day but I still believe he hopes to make some new friends. A dog park is a good idea for doggy socialism. However, spending a whole day/night with the different dogs could be a completely different experience for your furry friend. They could learn from each other, interact with each other and even form friendships.
Therefore, being a pet sitter can give us chances to know more about our little fellers.