Being a current Skywest employee, from what I know, we have a $5.00 per segment charge and it's $.01 per mile. Now they added a fuel surcharge as well. Then again there's the "free" 6 roundtrips per year that is good for anyone which includes you, parents, friends, etc. I haven't used them yet or flown non-rev on Delta yet so I'm not sure. I personally fly on United because they don't charge anything and international flights on economy is free too.

Oops I forgot to add that I'm a flight attendant so I have the enhanced travel benefits which is a bit different. I think regular employees have ID90's or something.