I don't have any experience owning one, but I have been to every one in my area many, many times! I enjoy talking to people, so I've had a lot of conversations on the topic with owners and sales people. As with most all local retailers these days, foot traffic is way down and the internet competition is way up!
I'm all for supporting my LFS, and I always try to limit my livestock and chemical purchases to the local guys. Unfortunately, just about everything else can be acquired so much cheaper and most times even faster online.
I was talking to my favorite LFS owner just the other day and he is like most that I would guess stay in business....its not about the $, it's about the love for the hobby. He is more than just a retailer, he sources, grows, cultivates and cares for everything he has just like it was his own. His store is his life and you can definitely tell.
To me, it sounds like an amazing opportunity if you have the ability and dedication to it. I don't think it will be an easy road, but hey, if it was easy, everyone would be doing it!