It took me a while to figure this one out, but it appears that Jet.com, which hasn't actually launched yet, is the online equivalent of the warehouse club. I laughed it off at first, but after reading a Bloomberg Business article and discovering that this guy is the one who started diapers.com, I have decided that he is probably the real deal. Anyway, it's free for six months, so the most I have to lose is, well, zero.
Oh, if you sign up through my link, they will shower me with glory. Well, not really, but I might get something. You can too, if you want to start a conga in the comments.