Mega-merchants like Amazon have done a huge disservice to small businesses, IMHO. They have ingrained into people that shipping should be "FREE." Nothing is free. I sent a document to Hong Kong recently in a FedEx envelope using "Economy" International service for $35. That's right, a document. Even if it's a small box, there is handling, tracking and shipping involved and in the end someone needs to physically deliver it burning expensive fossil fuels in most cases.
I've had my share of issues with Amazon.com and certainly don't agree with all of their policies and haven't always received good customer service, but that aside what gives you the impression that they give you free shipping? If you want the 2-day Amazon Prime shipping option, it costs you $80.00 a year (unless you were fortunate enough like I was to get a hold of a student ID and get one year of it for free when they were offering that promotion). They charge for everything they ship, even if the rates are fair. If you purchase a lot from them than it certainly pays to get Amazon Prime, although that does not cover items not fulfilled by Amazon directly.