To start a fad, you need people, they do the rest.
Popularity is key here, so spreading it will help like heck.
I don't think Doctor Who is a good fad to start, it's mainly a UK show, therefore it won't be as popular.
I for one, would like to set up something for Transformers or Elder Scrolls fan, as I'm a huge fan of both.
To do that though, would be extremely hard...