Dogs are very social animals, and it's important for them to keep up their contact with other dogs as much as social interaction is important for us. Of course, this can sometimes be more difficult than it sounds, as you may not know any other people with dogs of their own, or your schedule might make things complicated.
In this case, you'll need to look into alternative solutions if you don't want to deprive your pal of this very important aspect of his/her life.
Dog day school in Chapel Hill are a very interesting and unique solution to this problem, and frankly, they're pretty much the best way to tackle the issue! They're quite the recent invention, and they weren't popular at all some decades ago – but nowadays boarding kennels are quite widespread and available in all places.
The idea is simple, and it works much like a regular camp where you'd send your children to. Each dog is given its own kennel (most places separate dogs according to their sizes so that bigger ones get respectively larger kennels) and they've got a common playground on which they can do whatever they want.
Care is taken for the animals all the time, and all good places that offer these services tend to have very competent staff on-site to look after the dogs. You can usually count on a vet being available all the time as well, which can certainly be an important consideration, especially for some breeds which are naturally predisposed to problems.