What defines Web 2. 0 is the fact that the material on it is generated by the users (consumers) rather than the producers of the system. Thus, those who operate on Web 2. 0 can be called prosumers because they simultaneously produce what they consume such as the interaction on Facebook and the entries on Wikipedia.
David will never go to space again. I'm glad. What did it gain the McQuarries? What has it ever gained men? Have men ever brought back more happiness from the stars? Will they ever?