In theory, in order for free shipping offers to be successful, the company would have to generate enough incremental revenue and contribution profit to pay for the cost of the shipping promotion. However, we believe Amazon.com has consistently failed to generate anywhere near the amount of incremental revenue and profit needed to pay for the lost shipping fees.  -   Mark Rowen     Quotes
In theory, in order for free shipping offers to be successful, the company would have to generate enough incremental revenue and contribution profit to pay for the cost of the shipping promotion. However, we believe Amazon.com has consistently failed to generate anywhere near the amount of incremental revenue and profit needed to pay for the lost shipping fees. Mark Rowen
 Company