i just do the online thing from time to time. at first they need a year before they can approve to increase my credit line, i've recently increased my credit line about 2 months ago, and i tried this weekend and they doubled it again, now i have a $4000 limit on my blue student card, and $7400 on my blue cash card (the student card started off with a $500 limit and the blue cash started with $1700)
heck i can buy a car with these two cards theoretically... and i am still in $14k of stafford debt. heh.
but when i request online, it's pretty much instant approval, so i guess they must have your records ready constantly...