In fact, those sales are a whopping 80 percent increase over Lion's predecessor, Snow Leopard, Apple Chief Executive Officer Tim Cook announced during his company's iPhone keynote.
Cook compared Lion to the launch of Microsoft's Windows 7, which he said took 20 weeks to reach 10 percent of the Windows install base. For Apple, Lion was in use by 10 percent of the Mac install base in just two weeks.
The CEO also touted that the Mac platform has grown by 23 percent since last year, easily outpacing the overall PC market's growth of just 4 percent. Cook also revealed that the MacBook Pro and iMac are the number one selling notebook and desktop in the U.S.
He also boasted about the success of the thin-and-light MacBook Air, which he said competitors have been attempting to copy on their own.
With the Mac platform having an install base of 58 million users worldwide, Cook said there is a great deal of room for growth for Apple.