With the cost of USPS postage going up, I think this is warranted.
Not that I'm a seller, but I feel that many people don't know how much it cost to actually ship things. Bubble mailer, usps postage, tape, shipping label, and if you sell a lot of things the time to package all adds up.
I have no idea how these big online retailers can afford to offer free shipping. They must need to sell A LOT of things in order for the profits to offset the shipping costs. I would think places like Newegg or Bestbuy loses when a customer buys only 1 single dvd, blu-ray, or game and they ship it for free.