Several reasons: 1) people who go through us skip the screening steps and go straight to a on-site interview at the YC companies. 2) We've sent a bunch of people to most of these companies, and have a good idea what they are looking for. We help you avoid failing interviews for the reasons mentioned in this article. 3) Perhaps you have no trouble getting responses to your resume, but a lot of (strong) programmers do. We help them. 4) We help candidates negotiate offers.