There are no raises for recruiter, no one in a sales position is eligible for raises, the idea they have is that you will just need to "work harder" to get your commission up...but that isn't how it works if the account you have been placed on is not a high performing account.
Pay is low not only for travel nurse recruiters, but also for RPO perm placement recruiters. all mid level managers call it "commission" but it is NOT commission, it is INCENTIVE PAY, and their lawyers chose to word it that way so there are stricter laws about them having to pay you that. Also, their handbook on incentive pay (which you will never see until you have an admin issue with it) says that an employee is no longer eligible to receive incentive pay if they are no longer employed....that means you may NOT receive your last month of commission / incentive pay no matter how hard you worked. Or you may receive it, it really depends on the politics and what they feel like doing I guess. I know many employees who left who did receive their final incentive pay the next month, and one who did not, but they will not own to their mistakes because they care about the bottom dollar.
I did not work in travel nursing, but I knew many who did and as a recruiter you may have to deal with candidates who you have helped move across the country who have shipped all of their belongings and tell them that their assignment was cancelled.
They play favorites, not based on merit.