I was a Buffy fan (although not the kind who went to cons because I was a broke college student for most of its run), so I first heard about the Dresden Files because I saw on a Buffy forum that James Marsters would be narrating the first book. I am a voracious reader but I never got into audio books (unless you count those little Golden Books that came with 45 records back in the olden days), so I thought ehhhhh, do I really want to buy an audio book that's WAY more expensive than having the actual book?
But I was deep in the throes of my Buffy obsession, and I had high hopes that it would provide a better outlet for James Marsters than getting beat up by Buffy, so I finally caved and pre-ordered. I liked Storm Front, but it was an interesting experience for me because I was used to reading, not listening. I read very quickly, so listening to a book for hours and hours instead of tearing through the words myself in a fraction of the time taught me to savor books in a new way.
It's been slow going though, since the audio books were released in such a wonky order once Penguin took over. At one point, I had 1-4, 10, 8-9, 6-7, and was waiting for them to finally release 5 so that I could continue listening to the series in order, which meant that I was forced onto a 2 1/2 year hiatus. By the time they finally released Death Masks as an audio book, I had forgotten much of what happened in the first four books.
Thankfully I now have all of the audio books except Ghost Story. Once I got book 5, I decided to start listening to the entire series from the beginning but it was slow going, mostly because I'm now lucky enough to have a job with a very short commute so I was listening for about 15 minutes at a time. I was about halfway through Blood Rites when I went out of town. When I got back, I just forgot to pick up where I'd left off. I recently remembered about my stack of audio books so I started listening to Blood Rites from the beginning and just finished it today.
I haven't bought the Ghost Story audio book yet because I've read so many negative reviews that I don't know that I want to spend that much money on an audio book that I potentially won't enjoy. I'm considering just buying the book once I get that far in the series.
I first heard about the tv series thanks to the Buffy fandom (so of course there were many people who wanted James Marsters to play Harry), but I haven't watched it. I know that I'm usually disappointed in tv/movie adaptations if I've read the books first because all I can see are the changes, gaffes, and other annoying differences from the books. If I know that a book is being adapted and I haven't read it yet, I prefer to wait until after I've watched the adaptation so that the book is a pleasant improvement.
I've introduced a few of my friends to the series in the same way: whenever someone tells me they are driving across the country, I send them the first few Dresden Files audio books so that they have something to listen to while in those radio free areas, and by the time they've arrived at their destinations they're Harry fans!