I just ordered a pair of nude Okala ankle-strap heels at Lord and Taylor and found to my surprise that the site gave me both the 20%-off promo (code: SALE) plus another 20% off, which I think must be from their current shoe "Buy more, save more" sale. (Yes, I admit I'm a bit behind the times buying the Okalas, but it took me a while to come to terms with the ankle strap with my short legs.) The promo isn't supposed to stack, but maybe it was a particular sale on the shoes I was buying? It doesn't work on all the shoes -- out of curiosity, I tried putting the leopard-print Okalas in my cart (only available in 4.5M anyway), but I didn't get the double discount on them.
But if anyone else wants to try, you may be able to get the ones I did for $66 (regular price $110). Or perhaps find some other shoes at a bargain price...?