If you take a peek at Apple’s Online Store you’ll see that Apple is preparing to offer the Watch in-store in the United States and other launch countries, listing that the Watch is “available soon” on the Apple Store iOS app and Apple Online Store. The option is greyed and is not selectable by the user.
Up until this point, all Apple Watch orders including Watch bands must be ordered online, exclusively. Soon, customers will be able to order online and pick up their Watches in store. Upon arriving at the Apple Store, customers will be required to provide valid government photo ID and must match the name on the reservation and product.
Apple originally planned to offer the Watch in-store, but due to manufacturing issues and high demand, the company revoked the idea.