First, dogs learn to play with other dogs and improve their social skills. Second, dogs use up a great deal of energy during their time at day care, which makes them well rested for the evening when you return home from a hard day at work, and your energy levels are a bit exhausted too. Third, day care helps alleviate behavior problems. Trainers agree, that a vast majority of behavior problems (excessive barking, chewing, digging, ...) result from a lack of exercise.
Day care gives the dogs an opportunity to play, expend that excessive energy, thus avoid those potentially destructive behaviors. And finally, day care gives owner's peace of mind knowing their precious pup is well cared for. Essentially, guilt-free dog ownership!