Diapers.com will leave larger shoes to fill than Zappos
cpaik.com
cpaik.com
Diapers.com's customer focus is slightly different than Zappos - eventually at some point in time Diapers.com's present customers will no longer have any reason to continue shopping there (it's true for us today - we don't need anything from Diapers.com), whereas Zappos can potentially sell you shoes for a lifetime.
As an aside, I personally find purchases clothing (including shoes) online in the not-quite-right category. How can you ascertain the fit and aesthetic of a shirt or a shoe without actually holding it in your hand or trying it on?
In regards to purchasing clothing online, there are some startups making inroads in that category--Fits.me, the one that won the European startup competition, Plugg, comes to mind.
I am now approaching the one year mark with new twins, and I will have spent more on diapers and other baby supplies than I will spend on shoes in the next 20 years. I generally buy 2 pairs of ~$50 shoes a year, but I spend >$100 on diapers, wipes, bottles, etc. every month. And the stroller -- my mid-level, non-fancy double stroller was $200.
Other families that space out their children spend thousands of dollars over the course of 4-6 years. If they're happy, they'll be loyal. They'll tell the other parents they know about the site (parents do love to talk about such things). I can see how this will be amazingly successful. People seem to be spending more than ever on their children, too.
My wife is a "LT customer" of diapers.com, and this line made me think back to why: it was because they once shipped the wrong item in place of what we ordered.
When my wife called up the service line, she was surprised at how quickly they helped her out, that they overnighted the correct item, and that they didn't ask for the wrong item to be returned. Considering that I imagine that "ship the right items" is one of the first things a business like this would get right, and that (the LTV of a customer) > (overnight cost of baby cream), could it be that the mistake was intentional?