Wondering about excessive brake dust on front wheels

What is your question?

I recently purchased a 2008 Ford F150 crewcab truck that looked to be in perfect condition. It had right at 20k miles when I bought it. It now has approx. 22,500 miles and I am noticing that there is an excessive amount of brake dust on the two front wheels and I'm wondering why, after only driving it about 2500 miles. I'm not hearing any noise when brakes are applied, but braking response is slow.