I have never seen Amazon use a flat rate box, and the flat rate box is limited in sizeso they can only use it for a very limited portion of their inventory. For my shipments they seem to use UPS, FedEx and California Overnight about equally.
They always use it for my book orders. The largest flat rate box is 12" x 12" x 5-1/2",and they rarely need a box that big, even to ship 4-6 books.
This must vary by location, because I’ve never seen a flat rate box from Amazon either.
Specifically, check the prices on non-books/non-CDs versus what other stores or even the manufacturers charge. I’ve often found that the “regular” price claimed by Amazon is higher than you might find it elsewhere, and their “special” price is also often higher than sale or even regular prices at other retailers.
Also, on “Cyber Monday” when you’re supposed to be getting all of these good deals, I had a selection of stuff in my “cart”, including two DVDs I’d put in the day before. On that Monday when I logged in to check the prices, the DVDs had been bumped up in price since the day prior.
This is probably to avoid having to collect sales tax from you.
I have a dot com and initially rebilled my customers for the exact shipping charge. That turned out to be a pain in the butt because obtaining and transferring the shipping costs to the invoice was a pain and delay.
I then switched to a standard FedEx shipping charge of $45/job period. The actual cost could be $300 or $10 depending upon where the customer was located, how fast they needed the product, and how soon the custom-made product was shipped. The $45 shipping charge was based on the average of all shipping cards (some overnight, some ground, some heavy, some light).
The flat fee was a non-issue since it was designed to be a wash. It simplified billing and customers could budget with precision.
Of course, my products ranged from hundreds of dollars to thousands so the shipping costs never was really an issue. With lower cost items, I would have needed to choose a different model or, at least, a lower flat shipping fee.
Soo…bottom line, there are a number of considerations.
And then there are many merchants that choose to profit from shipping charges alone (the cd is free…you just pay (inflated) shipping). Heck, my credit card charges me extra if I wanted my electronic online payment “expited.”
I’ve even seen companys delay shipments for “ground orders” so that you would pay extra for over-night or 2nd day shipment.