Amazon

You spend money you don't own and you buy things you don't need

Today the online retailer hosts its third annual deep discount prime day

It might seem a bid to create

A day of wanton consumerism to rival single s day, an informal Chinese holiday turned online shopping spree.

But the deals are available only to members of prime, a subscription service, indeed, membership is the main product on sale.

For 99 a year subscribers get free two day shopping, streaming video and other such inducements

It's a powerful way to change consumer s habits

A bank estimates prime subscribers spend at least three times as much as un primed shoppers