I'm making my way through Seth Godin's Tribes book (Kindle version) and realizing how visible the lessons are, even in non-marketing/business areas. The other Sunday, I was in Brooklyn playing a game of pick-up soccer. I was the first person there and a few minutes later another guy showed up. He was knocking the ball around and I wanted to join. Not that it's a terribly important group, but I wanted to join. Right then, it was important to me to join that group.
The other piece of the book is about leading these groups. People not only want to join groups, but they want someone to follow - someone they can somewhat agree with who will point them (collectively) in the right direction. With the pick-up game, that was easy - whoever started forming the teams and getting the fields laid out, he was our leader and we were all happy to follow (since we really wanted to play).
Quite similar to business. I remember one of my first jobs was working at a coffee shop just south of San Jose, CA. Busy coffee shop with tons of regulars. A bunch of us didn't grasp the concept of a "club card" (ie, buy ten, get one free). The owner of the place explained to us all: people want to belong.
Funny how that hasn't changed in 20+ years (and likely much longer than that).