Test gave me 707 wpm. Not completely sure I trust it as it's trying to sell me a speed reading program. I reject the notion in the text that the three ways to improve reading speed are spped reading seminars, books, and computer programs.
The best way to improve reading is the same as the best way to improve your free throws. Lots of practice.
A 500 word book usually takes me around 4 hours. When I have time, I will often do that at one sitting - one of my favorite places to read being fast food restaurant dining rooms. Booths are comfortable and unlimited coke. This summer, I re-read the published books of the Wheel of Time series in about 4 weeks. That's something like 11,000 pages.
However, my reading speed varies quite a bit by subject matter. Novels that I am reading for entertainment are probably a lot faster, whereas philosophical or otherwise difficult texts are a lot slower.
I believe I read quickly because I have read often my entire life. In Elementary and Middle school, I read just about everything in my school library (which was pretty dinky) and re-read things I liked over and over.
Once I reached a certain skill level, the mechanics of reading kinda disappeared, and as my brain processes the text automatically, I feel more like I'm watching the story unfold than reading it. It's a lot like dribbling a basketball. At first, you really need to think about what you are doing with the ball, but if you play often enough, you just start doing it automatically.
Find books that interest you. Action, mystery, horror, erotica, whatever, and read, read, read them and your speed will increase. But its something you need to put work into. You can't master a skill without hours and hours of practice, no matter what that skill is.