Go to bing.com. search "endless.com", follow cashback link at top of search results.
Tons of shoes here, prices seem about average so this could be a good deal. A few things worth mentioning...
1. Make sure when you check out the cashback amount is shown, if not delete the items from your cart and start over.
2. If your total *after* BCB is over $100 you should automatically get another $20 off due to a running promotion.
3. Not sure how long the 40% will last, but Bing is ending the cashback program forever on July 31.