There was a service a few years ago called NetPlenish which would basically find you the best deal on the cart of items you were looking for from various online retailers like walgreens.com, soap.com, walmart.com, etc...

I used it a few times, but it was confusing who I was supposed to get customer service from when there were problems with the order. You would pay NetPlenish, who would process the order because the item was listed in stock. But if the item was out of stock and your order was messed up, who do you call? Who refunds you? NetPlenish or Walgreens? or in this case Jet?