A targeted resume is a resume that is customized so that it specifically highlights the experience and skills you have that are relevant to the job you are applying for. It definitely takes more work to write a targeted resume than to just click to apply with your exisiting resume. However, it's well worth the effort, especially when applying for jobs that are a perfect match for your qualifications and experience.
You will be doing more than just measuring up to the hiring criteria. You will be highlighting and promoting your qualifications for the position. In addition, you'll be saving the hiring manager some time, because he will be able to see at first glance why you are a strong candidate for the job.
If you're still not sure about taking the time, try it once or twice. One job seeker I mentioned it to grumbled a little at the extra work, but he was pleasantly surprised to get a phone call for an interview within a day or so of submitting his resume (and a subsequent job offer).
Image © Amanda Rohde