Bloomberg BusinessWeek this week said analysts peg initial sales of the iPhone 4S between two to three million units, with an analyst from research firm Yankee Group estimating four million units sold at launch.
Apple this week said pre-order sales for the iPhone 4S topped 1 million units in the first 24 hours of pre-order sales.
The figure surpasses the prior record of 600,000 units sold in one day made by the iPhone 4.
In addition, AT&T Inc., Verizon Wireless, and Sprint Nextel Corp. sold out of initial pre-order stock for the iPhone 4S days prior to launch.
The iPhone 4S began sale at brick and mortar retail stores Oct. 14.
The device will be sold in more than 22 countries by the end of the month.
The iPhone 4S includes the A5 Dual-Core CPU, 8MP camera, 1080p HD video recording functionality, iOS 5, and a new voice command protocol called Suri.
Suri can call, text, email, remind, and offer weather, stock, traffic, direction, and definition information via voice commands.
Battery is said to offer 8 hours of 3G talk time and 10 hours of video.
The 16GB SKU sells at $199, the 32GB SKU at $299, and the 64GB SKU at $399 after two-year contract.