Running is more fun when running together, as each member is motivated to run more often, and stay injury free. As you share stories, (gossip, issues) and pull one another along, the miles go by much more quickly. Lifelong friendships are formed in these mission-oriented, but laid back groups.
In each of our locations, pace groups (of usually 8-15) are set up according to current fitness level. A leader keeps the speed slow enough for all members, and enforces walk breaks from the beginning to the end.