Communities can be very strong. I add a link (in Dutch though) where you can see the strength of the community even it is not payed by anybody.
This is a website for Dutch amateur football team. Every club and even every team can register on this site. What are the benefits and fun you can have? It is a website where you can post the score of a match, who played, for what competition you played and who scored the goals. You can even add pictures, stories about a match and everybody can see this.
Some of my friends who I play with in a team do use this. When you ask them why they put time and effort into this, they say it is fun and you can follow your competitors in a funny way as well. And everybody likes it to know how many times they scored in their history.
Companies are apparantly also interested. You see some sponsors who support this site, and ofcourse give discounts to people who visit the site.
I just wanted to show you the strength of a community even though people are competitors of each other, but are willing to help and inform each other.
Greets, Boudewijn
Consumer Value Creation 
While I just wrote some comment on the blog of communities of Erwin about the benefits of communities and a counterargument to a possible disadvantage, it is nice to see a real life example of the strength of a community.
Thanks Boudewijn!!
Nice to see different examples from totally different product categories. Even in cases where there is no direct sale (or is it?), we can see that it is insightful to understand the individual behavior and decisions to participate in a community. Fun, to start with, is a very strong reason. But also, it is a nice way for football players to promote themselves (without wanting to describe them as products)…