AT&T ( says it’s activated more than one million iPhone 4S’ as of Tuesday, making it the most successful iPhone launch in the company’s history.  

AT&T was the first carrier in the world to launch iPhone in 2007 and is the only U.S. carrier to support iPhone 4S with 4G speeds, says Ralph de la Vega, president and CEO, AT&T Mobility & Consumer Markets. The iPhone 4S is also available via Verizon and Sprint.