Why don't you buy shoes at the mall and avoid the hassle of exchanges and wrong sizes and the ability to wear it out of the store? Clothes, to me, consistently sound like one of those silly things that doesn't work in terms of online shopping.
I pretty much exclusively wear Doc Martens. In any given shoe store there are at best 1-2 different styles of Docs. There is one outlet store in the US, in Portland, several thousand miles away from me.
Zappos has dozens upon dozens of styles of Docs, pretty damn close to every single one that's available. They have most of them in the size 13/14 I take, which can also be an issue at shoe stores.
In a transaction where you already know exactly what you want, then yes, it would most likely make sense to purchase online for the sake of price savings.
That is an excellent question, because that's exactly what I said prior to using them.
The answer is that their customer service is so good, and it seriously so easy to do exchanges that I don't mind not having my shoes right away.
So, what I sacrifice in instant gratification I gain in selection and the ability to see reviews. Additionally, they have enough information to say whether or not shoes are sized funny at all (a little too big in general, a little too small in general).
Seriously, the next time you buy a pair of shoes just try them out, it's mind-blowing.
But the point of a physical store is of course for the sales process to work. That interaction is pretty important, it's why sales staff have jobs. Using technology to abridge that since the first dot-com has consistently been lacking. The best shoes buying experience thing I've seen is Amazon's "experimental" endless.com.
I actually find Zappos' site (I've made two purchases from them) extremely lacking in terms of introducing products and detailing it. Here's why: Zappos isn't a shoes company, it's a logistics company. Their customer service and fulfillment efficiency is what makes them awesome, likewise with Amazon or Newegg. What they happen to focus on selling isn't important.
That said, it's why I think clothes or shoes or makeup or car shopping is so odd for people that don't quite know what they want in mind. These are products that kind of do need hands-on touching, smelling, trying, and so on. Then again, online shopping is huge business. I wonder if that would remain so without the physical stores present.