You must not be married.
While I am happy to grab whatever t-shirt is next in the closet (sometimes the wife tries to arrange them based on the next pair of pants/shorts in the dresser)... my wife is a fair bit more concerned about her look, even though she will often deny it.
It took me a while to realize, but Amazon's target market for quite a few things isn't geeks like us who want some random PC part or book delivered the next day... it's our wives/girlfriends who this is geared towards. Just watch the product video, all women, all into fashion. Sure, not all women are, but if you see enough of them in the wild you see how/why this is a smart move to target them.
Go a bit further, ask married couples around you: Who orders more on Amazon? Who has a higher income in the household? More often than not (doubly so in households with children), the wife spends more on Amazon while the husband is the one paying for most of it.
Note: I'm not saying any of this is good or bad (wrt who spends and who pays), simply that it is a smart move by Amazon to further exploit an area they've targeted for quite some time.