If you ever get a good answer, let me know. I'd love to be able to answer that question.
Ain't that the truth. You're right, they hold the upper hand, so you have to play the game.
Most of the time, HR isn't looking to fill any positions, they're just trying to keep the pipeline full for when a position comes open.
And don't get me started on Robert Half. Their reps don't get paid for filling positions, they must get paid for adding candidates to their "inventory."
Unless you're desperate, don't waste your time. You'll spend a couple of hours filling out paperwork and talking to the rep. After that, it's crickets.
They must be getting desperate, though. I received a call last week from them, wanting to "reconnect"...I've been gainfully employed for about 4 1/2 years (thankfully). I'll give him a courtesy call tomorrow, but that's about it. No one I know has had a good experience with them.