This is not customary. In fact I've never heard of it for placements. A broker for consulting work might take a finder's fee, but never for regular employment.
Way back when, like in the 1950s and 60s, employment agencies might take a percentage. The shift to more contract work, where the percentage is baked into the billed rate vs. what they pay, has ended this.
Way back when, like in the 1950s and 60s, employment agencies might take a percentage. The shift to more contract work, where the percentage is baked into the billed rate vs. what they pay, has ended this.