Apparently the answers lie within
OK so everything is changing. After a chat with Matt Desmier, the Head of Partnership Development at South West Screen, he put me on to a little book to help in the quest for understanding Transmedia. Thing is that the book is frightfully modern and available as a PDF for free ohmygodwhathappened.com
So now all I have to do is some more reading, but not via an Ebury or an Ibook, but a PDF book, circulating using Twitter. This must surely tick a Transmedia box or three.