Jumpseat policies on Delta and Mesaba?

[MrCoffee]

I'm sure this has been discussed many times, but wondering if I can get a quick answer on the number of offline jumpseats these two carriers allow on a flight. I checked the "view seats" on delta.com and the two flights I'm trying to get on have several seats open, just curious how the first come first serve jumpseat policies work, in other words, how easy is it to get stuck somewhere because there is one other jumpseater that gets to the counter before me? Don't jumpseat a whole lot on pax, so I'm a little green when it comes to this.

 

[big shacks]

unlimited for both

 

[MrCoffee]

'preesh