The average North American family has $1,000 worth of unwanted stuff in their homes. They can simplify their lives or buy new junk by joining the New Auction Culture via electronic yard sales. In FutureShop, Daniel Nissanoff describes a “post eBay” online auction culture where entrepreneurs establish “drop shops” for consumers to swap goods. Mr. Nissanoff, who sells used luxury goods this way, says online buyers still greatly outnumber sellers. But this will change as online auction houses help sellers get prices closer to true value — and certainly more than they’d get at a yard sale.