Rue La La is a flash sale site (a la Gilt Groupe, Amazon's MyHabit, and so on). Their inventory changes pretty quickly (something like 48 hours, I think), and

Rue La La is a flash sale site (a la Gilt Groupe, Amazon's MyHabit, and so on). Their inventory changes pretty quickly (something like 48 hours, I think), and different brands are featured during each iteration. NastyGal doesn't appear to have rolling inventory; rather it seems they have relationships with some set of brands, but the brands themselves aren't front and center. Moreover, NastyGal also appears to have its own brand, which RueLaLa does not (though Gilt Groupe does have its own Gilt Home (ie furniture) line).