Building "The Sword of the Dragon" brand: What's the advantage?

When I released the first The Sword of the Dragon novel I hoped to write the seven books and then expand with offshoot storylines in stand-alone novels and new series, much as Star Wars and Dungeons & Dragons have done.

We're looking at a fourth book in the main series to release later this year (titled In Search of Dragons) from AMG/Living Ink Publishers. I am maintaining control of many of the rights, therefore the Neverqueen series is releasing from my own imprint Flaming Pen Press. We will release Neverqueen 2: The Suffering Chalice in or before November 2014. I am excited for other books that I  am planning as well, including a novel detailing what happens to Specter after he secures the Key of Living Fire and vanished through the portal.

The advantage is that the story never has to end and as resources increase we can branch out into audiobooks, video games, and eventually other mediums.

I've placed a poll on the blog sidebar so that you can vote which title you'd like to see in audiobook format first.