Oh come on - where's your sense of humor? Really?You keep saying how much you LOVE credit cards, I thought it was a natural punch line and was surprised no one else had caught it.
Back to serious discussion though, I'm trying to figure out where you've gotten a credit card with a 3.9%. I've received solicitations for that kind of thing, but on mine that interest rate is usually either only on a balance transfer or is for a short time period only. 3.9 is a SCREAMING deal for credit cards. I'm not exactly a credit card expert, but I'm pretty sure that rate is highly unusual.
I have a Discover card thats at 0% until next summer. Credit card companies always have promotional offers.