Originally Posted by tripleT
"...its still up to the captain to say yea or nay if you can go..."
Last I looked the jumpseat still belongs to the Captain and it IS a professional courtesy from THE CAPTAIN to allow another carrier's employee [pilot] to ride in the cockpit - or in the cabin - for free.
Most airlines would like to do away with CASS, after all it cost them money with NO return to the bottom line. Contrary to what some may feel (or want) a free ride in the jumpseat is not a birthright. A C-207 Captain or a B-747 Captain, should both be given the opportunity to extent the courtesy. There is a reason they call it "Captain's Authority".
That said, the industry does have some captains (small "c") that use the jumpseat to punish other carriers or pilot groups who they think have done them wrong. IMO, that is SO wrong, but it seems to be best suited for a different thread than this one.