I think combined shipping can be a huge attraction factor for an Amazon or Walmart. If you want to buy a $150 mixer, but also, say, a $10 book and a $5 cable,

I think combined shipping can be a huge attraction factor for an Amazon or Walmart. If you want to buy a $150 mixer, but also, say, a $10 book and a $5 cable, you'll be able to put those all in one cart at those vendors and get free postage. If you go to some specialty mixer retailer, you'll have to buy the other items as a seperate transaction and pay for shipping on them. I know in my household, we definitely will ask around "I'm buying something from Amazon, so I'll already be spending $25, does anyone want anything else on that order?"