Ask HN: Buying ZapposVsRest

I was checking out shoe prices in Zappos for some Hush Puppies, and then decided to check the price if I bought directly from HP. Surprisingly there is a 5-10USD difference (HP is cheaper). I was wondering, why would people buy from Zappos instead of HP (I didn't check for other companies). I mean..is the "service" worth 5-10$?