Remember in every job you applied if you want it so bad and want to win over the rest you must have a killer cover letter and that cover letter should be related to what your applying for or else sorry for you, they will choose another contractor.
What if the job provider is unresponsive and my application was there for about 3 - 4 days, well in my part I don't choose employers who are not responsive for more than 2 days, I simply withdraw my application and save it for the next list of jobs offered.
Read more on how to write a killer cover letter, remember you must apply only if you know this job and you know you can do it, or you will ruin your work history or you won't get hired at all.