This offer is only for those with a Kindle with Special Offers:
Save on Select Shoes (Get $30 off when you spend $100 on Women's pumps & Men's dress shoes)
Click on offer, then click on the link on the offer page to receive an email with the promo code. Sign-up for this offer expires on April 29 (it says the 30th on your Kindle, but the promotional page sets the cut-off as the 29th).
You'll get an email (right away), a link to the Special Offer page and a promotion code to enter at checkout. Once you have the promotional code, you have until May 31, 2012 to complete your purchase. Like previous offers, this one requires you to use the full checkout process in order to enter your promotional code. Also, like all Amazon sales that use promotional codes, if you have a gift card balance, you must use it for the payment (if there is not a sufficient balance, then you can pick which credit card or other payment to use).
Limit one offer per customer and per device.
You can add one or more qualifying pair of shoes to get to the $100 minimum and there seem to be a lot to choose from. One the Women's side, it is all dress heels, from what I can see, but I saw loafers in the men's selection (apparently the 31 most popular choice, right now). Personally, I don't buy shoes mail order, but you do have the protection of the return policy at Amazon on these (if you do return them, the promotion amount is subtracted from any return value, of course).