Woo, I got my email! It's $15 in-store only, on $35 purchase, and you have to print off the email to get the redemption.
I agree that you VIB ladies should have gotten something bigger. I remember Sephora advertising that you would get a rebate depending on what you spent. It doesn't seem very sporting to change that after the fact. I think you should have gotten an actual gift card (not just a coupon, because that's what this is) and there should have been brackets. Ie, spend $500, get $20, spend $1000, get $40, etc. Maybe even a little book of coupons for the next year, too. Something a bit more... perky?