I used my coupon today. I got Black Dahlia and Radiate Lip Tars, and NARS Storm Bird polish. My total was exactly $50. I know I could've used the card for less than $50, but I'd have to pay for shipping. I really wanted those two Lip Tars since they were previously out of stock, so I added the polish to avoid shipping. The polish was something I was going to get eventually, and the savings to get it now is higher than the usual 20% off.
My account still hasn't updated to VIB, so I used the $15 amount I was given before it expires. I called and was told that I could get the missing $5 back once my account updates. When my account updates to VIB, I'll save the 10% off welcome coupon to use in January with another gift card I'm getting next week. That way the purchase will count towards qualifying for the next VIB year.