While visiting an Apple store in California on Friday, the tech behemoth's CEO told CNBC that reaction to the smartwatch has been "extraordinary."
"Customers have been giving us great feedback and orders have been great, as well," Cook said.
Surrounded by a crowd outside the Palo Alto store, Cook also showed off his watch of choice, a stainless steel model with a white band.
The hyped watch became available for pre-order early Friday morning and sold out online within hours. Buyers of some models won't receive their devices until May, while others will have to wait until July.
By midmorning Friday, "Apple Watch" listings surfaced on eBay.
Despite customer enthusiasm and mostly positive reviews for the watch, Apple stock has reacted sluggishly. Shares in the company were 0.4 percent higher Friday afternoon.
—Reporting by CNBC's Josh Lipton.