Drop shipping is a decades old technique. But it has been popular in e-commerce, because it avoids the need for warehouses. Or does it? As Amazon found out in its early days, there can be fulfillment problems associated with drop shipping, when the supplier can't deliver on time. Also, there's the problem of what to do with returns, which often can't be returned to the supplier. It's still useful, but it's not a panacea.E-Commerce Techniques: Drop Shipping