Yes, very good points, Chris and Hazel. And, of course, that's why many cut their writing teeth on fanfic - because they have a ready-made set of characters there that everyone recognises instantly and they don't need to do the groundwork on. That's very true.
In fact, now that you've pointed it out, I dare say that was the case for me too, when I started writing fanfic. It's so lost in the midsts of time that I've forgotten, but I'm pretty sure it must have been easier to start with established characters than it was to launch into my own.
LabRat