Apple continues to prove that the excitement surrounding the company's iPhone has not died down. With the introduction of the iPhone 6s and iPhone 6s Plus this past weekend, Apple sold 13 million units.

Apple announced the 13 million figure on Monday for sales from Friday to Sunday. Friday at 8 a.m. local time was the first chance to purchase the new iPhones at Apple Stores and authorized retailers, CNET reports.

Last year, when the iPhone 6 and iPhone 6 Plus were introduced, Apple sold 10 million units during the first three days. Even though this year's new iPhones are in the "s" cycle, where only internal improvements are made, iPhone fans were excited about some of the new features.

"Sales for iPhone 6S and iPhone 6S Plus have been phenomenal, blowing past any previous first weekend sales results in Apple's history," Apple CEO Tim Cook said in a statement. 

Apple needs its iPhone sales to be excellent for each release because sales of iPhones contribute to about two thirds of their revenue. While other phone makers are seeing slowing growth and increased competition from cheaper models, Apple is enjoying continued success with their iPhones.

The big sales numbers for the iPhone 6s and iPhone 6s Plus could start slowing down after the big weekend, but the iPhone 6 and iPhone 6 Plus continued to sell well after its big opening weekend.

The iPhone 6s and iPhone 6s Plus added a better camera, 3D touch, a stronger aluminum build, a brand-new, faster processor and a stronger glass screen. 

Apple decided to offer the new iPhones in China at the same time as they were offered in the U.S. Last year, China had to wait for regulatory approval before they could get the new iPhones. Apple also announced Monday that 40 additional markets in the world would see the iPhone 6s and iPhone 6s Plus on Oct. 9, including Russia, Spain, Italy and Mexico.