Shoe Shopping - Who to choose?

So I think there are a few main choices when shoe shopping, like Zappos, Piperlime, and Bluefly so who to choose? I personally like Zappos. They have free shipping both ways and they have a huge selection of shoes. The only real issue I have with them is the lack of promotions. I mean I signed up to their email list and I haven't gotten and good discounts, just a bunch of junk mail about shoes that I don't even want. Once I even got a men's shoes advertisement, so that wasn't cool. However, Bluefly does have the hottest shoes which makes a difference for them...