It's interesting that the article mentions LOTR and HP because, even though this book is less popular than LOTR and less recent than HP, I always thought the Mists of Avalon did more to convert people to paganism than anything else in the history of ever. I back this up with my personal anecdote of when I was a teenager. I belong to a church of religious exploration and general shenanigans and so I followed my then girlfriend into the church basement for the pagan chalice circle/coven that was held there. On the first day, the high priestess/chair/mediator held up a copy of the Mists of Avalon and was all: if you're here for this, you probably won't enjoy circle/coven; please recall that the mists of avalon is a work of fiction and here we only do solid magic. She then gave people a moment to leave and several actually did.