Don’t spit your coffee at the computer screen just yet. I’m talking predominantly in terms of sales over time. I know all you belle-lettristic types don’t like to think about anything but Art, but units-shifted is a factor that matters. It is what shapes the literature industry.
This is a good essay by author Mark C Newton about the predominance of Fantasy Fiction over Science Fiction as trend in book sales.
I personally love Fantasy, and tend to read more of it than hard Sci Fi so this read pretty true to me. I think that in some circles of Sci Fi purists my blog would be really more about Fantasy and Hollywood versions of Sci Fi action than about Hard Sci Fi writing. I just write about what interests me and the other fans in my life. I don't really bother worrying about labels - if I like it I like it.
However, labels are pretty key in terms of where in the bookstore items are displayed, what kind of cover art is employed, and what the chances are that any given person is going to pick up that book to flip through. From a marketing perspective its pretty powerful stuff. And well worth reading about and considering.
Then go out and pick up a book with a cover that you wouldn't normally look at. Try reading something outside your comfort zone. Used bookstores, Goodwill, and the Library are great places to skulk around. If you didn't pay much (or anything) for the book you have nothing to lose if you read 20 pages and decide you just don't like it. And you might have a great new experience to gain.
And while you are at Goodwill you can find cheap books to buy and sell on half.com or other places that buy and sell textbooks.