All you have to do is haggle. Customer service agents often have access to internal promotion codes that you can't find anywhere else, and they're willing to give them out to make a sale.
Simply contact the merchant's customer service center and ask for free shipping on your order. If that doesn't work, wait it out, literally. Let your order linger in your online cart and see what happens.
Retailers know that shoppers sometimes need a little push to complete a transaction, so they tend to send out special offers for free shipping to get you to click that checkout button.
So, the next time you want to buy something online, take advantage of these simple tips. You may never have to pay for shipping again.