An AT&T memo was leaked recently that gives us an interesting look inside one of the world's largest mobile carriers. This internal document lists some of ATT's recent milestones and major successes, most of which seem to be directly attributable to the iPhone.
First they state that Michael Jackson's death marked the peak number of text messages ever sent on their network, at its highest point, over 65,000 text messages per second were being sent. This blows even American Idol and the traditional New Years texting rush out of the water. Chock this one up to another sign of the times.
Next they celebrated 'iLaunch day 2009', which was a watershed moment for a number of reasons. It marked their best ever sales day, and their second best ever retail traffic day. It was also their largest order day, largest feature sales day, most upgrade eligibility check day, and most transactions processed day. AT&T states that 2009 launch day exceeded the launch, Black Friday, and Christmas sales days of 2008 by noon.
All this is just more evidence of how badly AT&T needs the iPhone to stay exclusive to them. If Apple moves to another carrier their sales are going to skyrocket, but ATT will not be able to make nearly as much money as they've become accustomed to. Once Verizon and other carriers start selling iPhones, who is going to want to go with AT&T?