I don't purchase a whole lot online. I love the physical act of shopping way too much. I don't like the thought of shipping costs and even worse, return shipping costs. So I must share with you my obsession with one exceptional site:
Endless.com. Oh-my-word. This site is a shoe-lovers dream. Not only is their selection literally 'endless', they also offer FREE shipping (often NEXT DAY), free return shipping within 365 days of your purchase, AND their %100 price guaranty. Crazy, I know. And equally important is the usability of the website. Their sort options are the best, the pages load super fast, and your wanted items can go into a convenient 'saved' box instead of going right into your cart. Currently, I have 21 shoes saved - because I'm sick like that. Oh, and if you do ebates (ebates.com, check it out), you can receive an additional percent off your purchase there as well.
Last week I bought a cute pair of Primo brand shoes. Darling, polka-dot flats with soleassage technology that was delightful for the bottom of my tootsies. Too bad they were too tight across the top and too high in the back, causing rubbing in all the wrong places. No problem. Free return shipping!
Typically, I would ask for commission from a company I promote so readily, but this is just that good. Happy shopping to you.