retail news in context, analysis with attitude has an interesting piece, noting that “this shopping perk has gone from a rare bonus to almost an entitlement in consumers' minds. Nearly half of transactions last year involved free shipping, and 61 percent of consumers say they will cancel their purchase if free shipping isn't offered, according to a recent comScore survey.”

The story notes that free shipping can take many forms - from always free to everybody (think LL Bean) to free shipping to members only (think Amazon Prime), from free shipping for a minimum order size to free site-to-store shipping.
KC's View:
I’ve been saying for years that free shipping - however you construct it, and I’m a big fan of the Amazon Prime program - was going to be a cost of doing business for e-tailers, and that they were going to have to start figuring out the economics.