Earlier quoted context omitted.
20-25% of salary isn't uncommon, and salaries of 120 K in technology is seniorish developer range where I work (Philly and NYC). My business model is different now, but when I did pure contingency work a 30K fee wasn't uncommon.
Do you have to wait a certain period before you get paid? Does this also work for in-house recruiters? Quite fascinating area really.
In-house recruiters are not usually paid fees like agency recruiters - they might get bonuses, but most in-house are paid mostly in salary with smaller performance bonus. Agency recruiters are usually paid little (sometimes nothing) in salary with most comp coming via commission.
This explains bad recruiter behavior, or at least much of it. Every deal might be 10-20K in the recruiter's pocket. For that amount of money, some people will do things they wouldn't normally do, and morals go out the window.