Gee, between the "Why back in my day..." postings and the Sex in D&D thing, it may not be possible to get this back on track, but I will try one more time...
If licenses are so important to products, how come no licensed RPGs have taken off -- Star Wars, Star Trek, Wheel of Time, Lord of the Rings, (insert your favorite here)?
How come for the card games, some games succeed and others don't AND it is not the strongest license that generates the most sales?
Despite opposing views, I do not see DragonBall Z as a stronger license than Star Wars or Harry Potter. DBZ has much less visibility, much less marketing, etc.
I think it is the game that overwhelmingly matters. The reason that the DBZ and LotR card games are successful is because of the quality of the game design and not the strength of the license.
In fact, I believe the reason the licensed RPGs have not done well is because licenses invariably come with restrictions on what you can do with the game design (can't kill Indian Jones, e.g.) that stifles creativity and harms game play.
Victor