The important take-away from the previous two parts is that, although my friends weren't especially familiar with the new-gaming idea of collectively creating a campaign (say that three times fast), they took to it very easily with some prompting. Gamers of every generation are creative types, and they may start from the assumption that the GM is going to be mostly in the driver's seat, but when you open the door to everyone's contributions they are on board.
Some gamers don't engage in a deep way with roleplaying games, of course, but that's the point of everyone building these things together; if someone is shy or feels like their ideas aren't good, the rest of the group is there to give them encouragement and suggestions. Eventually people warm up to the idea that the game belongs to us all.
The good news for GMs coming from an older generation of gamers is that this solves a number of problems that those of us in the Big Chair faced, back in the day. Firstly, and perhaps most importantly, it proceeds from a place of player engagement with the material. By drawing your game from the contributions of everyone at the table, you're sure to get a game that is interesting to the maximum number of people.
Secondly, many times in my formative years as a GM, players would have very little idea what they were getting into when they sat down at the table and made up characters (or even came to the table with one pre-generated). The chances were good that you'd get a random group of characters with very little to connect or motivate them. By creating characters and situations as a group, you implicitly create a working template of relationships between the characters.
Thirdly, if players know more about the game and feel a sense of ownership going in -- and in this game, they know as much as I do, barring what I pull in from the Call of Cthulhu rulebook and the Los Angeles sourcebook -- the more they feel ready to make creative contributions down the line. You're setting up a different kind of relationship between the GM and the players at the table as a foundation; they know from the start that they are considered co-creators whose contributions are welcome. For me, this is much better than the kind of "lonely fun" that some players get from writing elaborate backstories for their characters. If there is awesome character stuff to be had, get it on the table.
You also get the fringe benefit of built-in suspense. The players in this game -- which I've called Nocturne -- know enough to be spending their downtime wondering what's going to come next.
And hopefully, thinking about what they're going to introduce and contribute to the game, too.