Sending out 300 resumés in a month is the wrong strategy, as it shows you don't care about the posting. If you are willing to invest that little effort, you are basically playing a lottery against all the other people doing the same thing. You are far better off being selective and persistant. If instead of sending out 75 resumes a week, you spend a concerted effort on applying to a couple postings - and doing more than just sending your resume, I'm sure you'll have better results.