The Buy Box winner for a product is selected from the pool of eligible sellers offering that product based on, among other things, price and availability. Amazon will present the winning seller's "New" offering as the first choice for buyers using the "Add to Shopping Cart" box on product detail pages. For many sellers, this placement may lead to increased product sales.
After the Buy Box winner is selected, up to three Featured Merchant offers are displayed in the More Buying Choices box on the product detail page. The remaining seller offers (Featured Merchants and the remaining sellers) are available to customers who click the "new & used" link (or "new" link) at the bottom of the More Buying Choices box to go to the offer listing page.