Having been involved in the hiring process at a large financial organization on multiple jobs, there's actually more possibilities than they just already knew who they wanted to hire. True, sometimes it's the contractor guy that's sitting right there that you point to the job listing. Sometimes someone else gets jealous, takes that job listing down and posts a completely different one. Usually, though, it's not that AT ALL. A lot of times they do the interviews and because of a technicality decide to scrap the process and just repost the same job with a slight word change or at a different level. Then, you COULD apply all over again but it's just going to be awkward.

Usually, what happens is they post the job, call the agencies, choose the longest resumes, and then do the interviews. They'll then pick a guy, get the guy in, find out that they know absolutely nothing but just have a big head with over-confidence, and then shuffle the guy around until the dude realizes their jig is up and then they'll go try the same scam at some other employer. The other option is during the interview process to ask the candidate infinite questions until they give up and hang up.