From what I've read (including one of your sibling comments), when it comes to CP there is much less of a seller and user dichotomy. Many times people are both

From what I've read (including one of your sibling comments), when it comes to CP there is much less of a seller and user dichotomy. Many times people are both consumers and producers. Some sites/networks will even require someone to submit new content before they can join to see other content (although I don't have a source for this and don't particularly care to dig one up).