The Apple Watch is the hot new device that Apple expected it to be. Since April, 2.79 million units of the Apple Watch have been sold, CNET reports.

The Apple Watch went on sale in April and research firm Slice Intelligence has tracked the number of units sold since then. The company told Reuters Thursday that customers are buying up the popular new device and some of them are also adding at least one extra band for the watch.

The data made available to Slice was based off analysis of 2 million email receipts of online shoppers in the U.S. Inside that group, 20,000 purchasers of the Apple Watch were analyzed by Slice.

The Apple Watch requires at least an iPhone 5 to run basic apps and receive notifications. It is Apple's first wearable technology device. The hot device can cost as much as $17,000 for the 18-karat gold edition, but the entry-level Apple Watch Sport can be purchased starting at $349.

Apple made the watches only available through online ordering. Finally, on Wednesday Apple made the Apple Watch available for customers to reserve online and then pickup in the store. 

Apple faces competition for smart watches from several companies. Sony, Samsung, Huawei, Motorola, LG and Pebble have all introduced or updated their smart watches recently.

The operating system for the Apple Watch will soon see an update according to the company. Last month, Apple announced a new version of WatchOS that will have improvements and include apps specifically designed for the device. The new operating system is set to be released in the fall.

During the announcement of the upcoming new operating system, Apple did not announce any updates on the sales of the Apple Watch. This meant that companies like Slice and other firms had to estimate sales on the watch.

Slice reported that 17 percent of Apple Watch buyers also added a second band to their purchase. The most popular band was the black sport color. The second most popular band was the Milanese loop band which is made of stainless steel and costs $149.

Apple is making great profits on each Apple Watch it sell, according to research firm IHS. It is estimated that it only costs Apple $83.70 to produce the Apple Watch Sport that they sell for $349. Additionally, Mac Rumors reports that the sport band, which sells for $49, only costs Apple $2.05 to make.