This is how it works in some cases. You call WWE and they ask you to send them your pic and recent matches. Sometimes they call you. One of my goods friends got booked two years after sending in their stuff. They called him out of the blue and asked for him to send them some recent matches.
In most cases, guys go down to FCW for the tryout and get put into the database and when they are in town they hit up the same guys to see if they are availble. (EX: Bill Bain, Bobby Shields) I know a guy that got bad scores but still is at every Raw, Smackdown and PPV within 100 miles, and has been used twice on TV.
You hit the ring about 2:00pm and are told the same thing every time. "You" don;t belong here. You are an extra. Either a jobber to put one of our guys that belong or security, Melinas poparazzi, ect. Guys are told that they are not to take pics, or brag to their buddies cause they are not shit.
Some interesting notes: Bobby Shields will tell you that they hate him. But he shows everyone the proper respect, and when Shamus was preparing for his tables match VS Cena he was the only guy that stepped up when asked "who wants to let Shamus put you through a table"? Now they use him alot.
Michael Anderson decided to go outside with the fans and sign autographs at a Raw in Baltimore. So the staff threw his bag outside. The next night Smackdown was at Richmond and he showed up, and was used in a dark. So sometimes you can mess up and still be used I Guess.