There's a value in that space - rent, overhead, staffing costs, etc. - that has to be paid back by a certain number of inventory turns per month. In other words, the onesies and twosies waste space. However, when that space doesn't cost anything, suddenly you can look at those infrequent sellers again, and they begin to have value. This was the insight that led to Amazon, Netflix, and all the other companies I was talking to.
Chris Anderson, The Long Tail: Why the Future of Business is Selling Less of More
business-strategy, marketing, sales, the-long-tail