If you build it, they may not come. And, if they come, you will likely not be able to monetize their contributions. An Important Lesson About Grassroots Media: "I take some solace in knowing that some other smart people -- who raised far more money from investors than we did -– also couldn't figure out how to make user contributed content work as a business."
The value point of content has shifted from one where we can make money off of content to one where content serves as a means of creating relationships with others...and then we, if so inclined, can make money from the development of our reputation through the process of engagement, interaction, and sustained contact.