Jobs and No Jobs

So the job market sucks yet people are still working. What can we do to get jobs? I have replied to at least 75 job postings in the last 12 months. Most I don't get any call back from. Some call me and want to do a telephone interview, which I do. Some want me to come in to interview. None have hired me yet. Why, am I over qualified? Is it because I am white? Is it because I am not 22 years old fresh out of college? Is it because I know what I am talking about? How about the fact that I come to work early and leave late? Whatever the reasons, it's just not happening. I am really stressed out about it.